Debris Mitigation Device With Rotating Foil Trap And Sealed Drive
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Solution Overview
Problem
Existing debris mitigation devices for EUV radiation sources in lithography systems have short service life due to contamination and mechanical wear, as they require vacuum-compatible motors without lubrication, limiting operational periods to around 100 hours.
Innovation Solution
A debris mitigation device with a rotating foil trap and a drive unit enclosed in a gas-tight casing, where a sealing gas flows through a narrow gap between the driving axis and the casing, preventing contamination and allowing the use of conventional, oiled bearings for extended service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If vacuum-compatible motors with unlubricated bearings are used to avoid contamination from hydrocarbon vapors, then the purity of the vacuum environment is improved, but the service life of the drive assembly deteriorates
Solution Approach 1:
The drive assembly is segmented into two separate environments: a sealed motor compartment containing the lubricated motor and bearings, and an unlubricated bearing compartment for the driving axis. This segmentation allows each component to operate in its optimal environment without contaminating the other, resolving the contradiction between avoiding hydrocarbon vapor contamination and extending service life.
Solution Approach 2:
A sealing gas (inert gas or vacuum) acts as an intermediary between the motor compartment and the driving axis compartment. The sealing gas prevents hydrocarbon vapors from the lubricated motor from contaminating the vacuum environment, while allowing the motor to operate with lubrication for extended service life.
2Duration of action of moving object
If conventional lubricated motors are used to extend service life, then the durability of the drive assembly is improved, but the contamination of the vacuum environment deteriorates
Solution Approach 1:
The drive assembly is segmented into two separate environments: a sealed motor compartment containing the lubricated motor and bearings, and an unlubricated bearing compartment for the driving axis. This segmentation allows each component to operate in its optimal environment without contaminating the other, resolving the contradiction between avoiding hydrocarbon vapor contamination and extending service life.
Solution Approach 2:
A sealing gas (inert gas or vacuum) acts as an intermediary between the motor compartment and the driving axis compartment. The sealing gas prevents hydrocarbon vapors from the lubricated motor from contaminating the vacuum environment, while allowing the motor to operate with lubrication for extended service life.
3Object-affected harmful factors
If special gas-tight motors are used to minimize outgassing, then the purity of the vacuum environment is improved, but the ease of manufacture and operational reliability deteriorates
Solution Approach 1:
The drive assembly is segmented into two separate environments: a sealed motor compartment containing the lubricated motor and bearings, and an unlubricated bearing compartment for the driving axis. This segmentation allows each component to operate in its optimal environment without contaminating the other, resolving the contradiction between avoiding hydrocarbon vapor contamination and extending service life.
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 significantly enhances the service life of the drive assembly by preventing contamination and allowing the use of standard motors, reducing the risk of mechanical wear and extending operational periods beyond the limitations of vacuum-compatible systems.
Implementation Method 1
a sealing gas is supplied through a narrow gap between the driving axis and the casing, preventing contamination
Implementation Method 2
The debris particles, in the case of atoms or ions, slow down by the collisions with the gas atoms and are deflected from their original flight direction
Data Source
AI summary
The present invention relates to a debris mitigation device for use with a radiation source (2) generating optical radiation, in particular extreme ultraviolet radiation (EUV) or soft x-rays, and emitting undesired substances and/or particles which can deposit on optical surfaces in a radiation path of said radiation source (2), and to a corresponding drive assembly. The debris mitigation device comprises at least one rotating foil trap (5) and the drive assembly. The drive assembly comprises a driving motor (14) and a driving axis (10), to which the rotating foil trap (5) is fixed. The driving motor (14) and bearings (13) supporting the driving axis (10) are enclosed in a casing (20) having an aperture for the driving axis (10) and at least one outlet opening (21) for a sealing gas. The outlet opening (21) is connectable to a pump for pumping out the sealing gas. The aperture is designed to define a gap (23) between the driving axis (10) and the casing (20), wherein said gap (23) is connected to a supply pipe (19) for supplying the sealing gas through said gap (23) into said casing (20). The proposed debris mitigation device allows the use of conventional driving motors and oiled or lubricated bearings without the risk of contamination of the vacuum chamber in which the debris mitigation device is used. This results in an enhanced service life of the driving assembly.