Pellicle Breakage Region for EUV Lithography Contamination Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
EUV lithographic apparatuses face challenges in maintaining the cleanliness of patterning devices due to the lack of effective pellicle solutions, as traditional pellicles are not suitable for EUV lithography, leading to potential contamination and defects in the pattern projected onto substrates.
Innovation Solution
A pellicle with a breakage region designed to preferentially break before the rest of the pellicle, allowing for controlled failure and containment of debris, along with a sensor system to monitor the breakage and mitigate contamination, and a debris mitigation apparatus to direct debris away from the sensitive areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a pellicle is used to protect the patterning device from contamination, then the cleanliness of the patterning device is improved, but the risk of pellicle breakage and debris contamination increases
Solution Approach 1:
The pellicle is divided into a functional area and a breakage region. The breakage region is specifically designed to be the weakest part of the pellicle structure, segmented from the functional protective area. This segmentation ensures that when breakage occurs, it is confined to the predetermined breakage region rather than propagating through the entire pellicle, thus protecting the patterning device from debris while maintaining the protective function in the functional area.
Solution Approach 2:
The potential harm of pellicle breakage is converted into a beneficial controlled failure mode. By designing the breakage region with specific structural characteristics (such as reduced thickness or integrated weak points), the pellicle is engineered to break in a predetermined manner that minimizes debris generation. The breakage region acts as a sacrificial element that fails first, preventing uncontrolled breakage of the functional pellicle area and thereby converting the harmful effect of breakage into a controlled, minimal-contamination event.
2Object-affected harmful factors
If the pellicle is positioned close to the patterning device for effective protection, then contamination prevention is improved, but the risk of shadowing effects and interference with the radiation beam increases
Solution Approach 1:
The pellicle structure employs local quality variations through the breakage region design. The breakage region has different structural properties (such as reduced thickness or modified material composition) compared to the functional area, creating localized zones with specific optical and mechanical characteristics. This allows the pellicle to be positioned close to the patterning device for effective protection while the breakage region's specialized properties minimize interference with the radiation beam, balancing protection effectiveness with optical performance.
Data Source
AI summary
A pellicle suitable for use with a patterning device for a lithographic apparatus. The pellicle comprising at least one breakage region which is configured to preferentially break, during normal use in a lithographic apparatus, prior to breakage of remaining regions of the pellicle. At least one breakage region comprises a region of the pellicle which has a reduced thickness when compared to surrounding regions of the pellicle.