EUV Pellicle Strength Reinforcement via Carbon Nanotube Composite
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
EUV lithography pellicles face challenges with fragility due to low strength and non-uniform EUV light intensity caused by support structures, and high light absorption leading to reduced throughput in semiconductor fabrication.
Innovation Solution
A pellicle design incorporating a first inorganic layer with a low extinction coefficient, a coupling layer with catechol-functional organic materials, and a strength reinforcing layer featuring carbon nanostructures, such as carbon nanotubes, which enhances coupling strength and mechanical durability without the need for a separate support structure, and a porous thin film pellicle with nano-sized holes for improved transmission and strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a single thin film layer of silicon is used for the pellicle, then EUV transmission is adequate, but the pellicle becomes fragile and easily torn due to low strength
Solution Approach 1:
The patent applies composite materials by combining a thin silicon film layer with a carbon nanotube mesh structure. The silicon film provides EUV transmission while the carbon nanotube mesh provides mechanical strength, creating a composite structure that resolves the contradiction between transmission and strength. The carbon nanotubes are integrated throughout the silicon film, forming a hierarchical composite material that maintains both optical and mechanical properties.
Solution Approach 2:
The patent utilizes a porous structure in the form of a carbon nanotube mesh that is integrated with the silicon film. This porous architecture allows EUV light to pass through while providing mechanical reinforcement. The porous nature of the carbon nanotube network enables light transmission while the interconnected structure provides tensile strength to prevent tearing.
2Strength
If a support structure is added to improve strength, then tearing and sagging problems are reduced, but non-uniformity of EUV light intensity occurs
Solution Approach 1:
The patent merges the support structure function with the EUV transmission function by integrating carbon nanotubes directly into the silicon film. This eliminates the need for separate support structures that would cause non-uniform light intensity. The carbon nanotubes are distributed throughout the film, providing uniform mechanical reinforcement without creating optical path differences that would cause intensity non-uniformity.
Solution Approach 2:
The carbon nanotube mesh acts as an intermediary that provides mechanical strength without interfering with EUV light transmission. The nanotubes are sufficiently thin and transparent to EUV radiation that they serve as a mediator between the silicon film and the required mechanical support, avoiding the optical interference that would occur with traditional support structures.
3Reliability
If a pellicle is made to protect the mask, then particle attachment is prevented, but light absorption increases and throughput decreases
Solution Approach 1:
The patent uses an extremely thin silicon film structure combined with carbon nanotubes to maintain protection while minimizing light absorption. The thin film architecture reduces the total material thickness that EUV light must pass through, thereby reducing absorption. The carbon nanotube mesh provides structural integrity without adding significant optical path length, maintaining high throughput while ensuring mask protection.
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 increases the pellicle's mechanical strength, maintains high EUV transmission, and prevents non-uniform EUV light intensity issues, allowing for thicker films with enhanced durability and reduced light absorption, thus improving semiconductor fabrication efficiency.
Implementation Method 1
a strength reinforcing layer disposed on the first coupling layer and including a carbon nanostructure
Implementation Method 2
a first coupling layer disposed on the first inorganic layer and including an organic material having a functional group belonging to the catechol group, wherein the first coupling layer increases coupling strength between the first inorganic layer and the strength reinforcing layer
Implementation Method 3
a first inorganic layer including an inorganic material with an extinction coefficient less than or equal to 0.02
Data Source
AI summary
A pellicle for EUV lithography is provided. The pellicle for EUV lithography may improve strength of a pellicle film by having a strength reinforcing layer including a first coupling layer and a carbon nanostructure disposed on a first inorganic layer, the first coupling layer here increase coupling strength between the first inorganic layer and the strength reinforcing layer, and a strength reinforcing layer including a carbon nanostructure. Also, a pellicle for EUV lithography according to another embodiment and a method of fabricating the same are provided. The pellicle for EUV lithography includes a plurality of holes and is a porous thin film made of a material with an extinction coefficient less than or equal to 0.02, and a diameter of the holes is less than or equal to 1 μm. Accordingly, improved strength is achievable because thickness may be made large with still having high EUV transmission.