Gas Spring Acoustic Damping for Lithography Vibration Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vibration isolation support devices for lithographic apparatuses have stiffness that is not sufficient to accurately transfer small feature sizes, leading to errors due to resonant responses.
Innovation Solution
A support device with a gas chamber under pressure and a section of acoustic damping material to separate gas regions, reducing stiffness and damping resonant frequency responses, thereby minimizing vibration transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a vibration isolation support device with small stiffness is used, then vibration isolation is improved, but resonant responses cause errors in transferring small feature sizes
Solution Approach 1:
An acoustic damping material is introduced as an intermediary element within the gas chamber of the airmount. This damping material absorbs acoustic energy and dampens resonant responses of the gas spring system, preventing the resonant vibrations from being transferred to the lithographic apparatus while maintaining the low-stiffness vibration isolation properties
Solution Approach 2:
The acoustic damping material changes the dynamic parameters of the gas spring system by introducing energy dissipation mechanisms. This modifies the resonant frequency characteristics and damping ratio of the system, allowing it to maintain low stiffness for vibration isolation while suppressing resonant responses that would otherwise compromise precision
2Manufacturing precision
If conventional airmount with positive stiffness is used, then resonant responses are reduced, but vibration isolation performance is insufficient for transferring smaller feature sizes
Solution Approach 1:
The airmount system is enhanced by combining the gas spring mechanism with acoustic damping material. This composite structure integrates the stiffness-providing gas spring with the damping-providing acoustic material, creating a hybrid vibration isolation system that simultaneously achieves both low stiffness for vibration isolation and resonant response suppression
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 effectively reduces vibration transfer and overlay errors in pattern formation by lowering the stiffness of the support device and damping resonant frequencies, ensuring accurate transfer of small feature sizes.
Implementation Method 1
a gas chamber containing an amount of pressurized air and a moveable member partly positioned in the gas chamber. The pressure of the air exerts a support force on the moveable member
Implementation Method 2
a section of acoustic damping material, arranged at a location within said gas chamber such that it separates first and second gas containing regions within the gas chamber
Data Source
AI summary
A support device configured to support a first part relative to a second part, minimizing the transfer of vibration between the two parts, includes a supporting system configured to use gas under pressure to provide a support force between the first and second parts; a gas chamber connected to the supporting system and configured to contain the gas under pressure and provide the gas under pressure to the supporting system; and a section of acoustic damping material, arranged at a location within the gas chamber so as to separate a first gas containing region and a second gas containing region within the gas chamber, wherein the section of acoustic damping material has a first side and a second side, wherein the first gas containing region is on the first side and the second gas containing region is on the second side.