Reticle Chuck Cleaner Vacuum Cleaning EUV Lithography
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Solution Overview
Problem
In EUV lithography, the large electrostatic chucking system used in EUV exposure apparatuses is prone to foreign matter accumulation, leading to pattern deformation and increased downtime due to the need for atmospheric pressure cleaning, which hampers the operability and efficiency of the EUV scanner.
Innovation Solution
A reticle chuck cleaner with a quartz substrate coated with a multi-layered film, a chromium electrode, and an adhesive containing acrylate copolymer is used to adhere and remove foreign matter from the chucking mechanism without breaking vacuum, allowing for efficient cleaning within the vacuum chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a large electrostatic chucking system is used to provide sufficient holding power, then the chucking capability is improved, but foreign matter accumulation increases leading to pattern deformation
Solution Approach 1:
The patent divides the chucking mechanism into two functional regions: a large-area first chucking region for providing sufficient holding power, and a smaller second chucking region specifically designed for cleaning operations. This segmentation allows the system to maintain strong chucking capability while dedicating a separate zone for foreign matter removal without interfering with the primary chucking function.
Solution Approach 2:
The patent introduces a cleaner mechanism as an intermediary component that operates within the vacuum chamber. This cleaner uses a cleaner chuck to hold and position cleaning tools (such as brushes or cloths) that can remove foreign matter from the reticle chuck surface, thereby mediating between the chucking mechanism and the foreign matter problem without requiring vacuum breaking.
2Object-affected harmful factors
If cleaning is performed by breaking vacuum to atmospheric pressure, then foreign matter is effectively removed, but downtime increases and operability decreases
Solution Approach 1:
The patent performs cleaning operations within the vacuum (inert) environment of the exposure chamber rather than breaking vacuum to atmospheric pressure. The cleaner mechanism operates in the vacuum state, using vacuum-compatible cleaning tools and methods that effectively remove foreign matter while maintaining the vacuum seal, thus eliminating the need for time-consuming vacuum breaking and re-establishment cycles.
Solution Approach 2:
The patent implements a preliminary cleaning action by providing a cleaner that can be positioned and operated on the reticle chuck before exposure operations begin. The cleaner chuck can hold cleaning tools ready for use, and the cleaning process can be performed quickly during brief intervals between reticle changes or maintenance periods, preventing foreign matter accumulation without causing significant downtime.
3Force
If a larger chucking region is used to compensate for electrostatic chucking limitations, then holding power is maintained, but the area susceptible to foreign matter increases
Solution Approach 1:
The patent segments the chucking region into a first chucking region with larger area for maintaining holding power and a second chucking region with smaller area that serves as the primary cleaning zone. This segmentation allows the system to utilize the full area for chucking while having a dedicated, manageable region for effective cleaning operations, reducing the practical impact of foreign matter accumulation despite the large overall area.
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
This solution enables rapid and effective cleaning of the reticle chuck within the EUV exposure apparatus, reducing downtime and maintaining vacuum conditions, thereby enhancing the operability and reducing manufacturing costs of semiconductor devices.
Implementation Method 1
an adhesive which contains an acrylate copolymer as a main component
Implementation Method 2
an electrostatic chucking system is used
Data Source
AI summary
According to one embodiment, a reticle chuck cleaner for cleaning a reticle chuck of an EUV exposure apparatus includes a substrate having a shape to be carried to the reticle chuck of the EUV exposure apparatus, and an adhesive formed on one of the main surfaces of the substrate.