EUV Light Concentrating Mirror Exhaust System
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Solution Overview
Problem
Existing extreme ultraviolet light generation apparatuses face a challenge in maintaining the reflectance of EUV light concentrating mirrors due to the deposition of fine particles, leading to reduced EUV light output.
Innovation Solution
The apparatus incorporates a chamber configuration with a second exhaust port positioned opposite to the EUV light concentrating mirror and a gas exhaust amount adjustment unit to control the ratio of exhaust gases, effectively directing residual gases away from the mirror and reducing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single exhaust port is used in the chamber, then the device complexity is reduced, but fine particles deposit on the EUV light concentrating mirror causing reflectance degradation
Solution Approach 1:
The exhaust system is segmented into multiple exhaust ports positioned at different locations within the chamber. The first exhaust port is positioned to exhaust gases from the plasma generation region, while the second exhaust port is positioned opposite the EUV light concentrating mirror to exhaust gases that may carry fine particles. This segmentation allows targeted removal of contaminants before they can deposit on the mirror surface, resolving the contradiction between simple single-port design and the need to prevent particle deposition.
Solution Approach 2:
The gas flow acts as an intermediary mechanism to transport fine particles away from the EUV light concentrating mirror. By introducing controlled gas flow through the multiple exhaust ports, particles that would otherwise deposit on the mirror are carried through the gas stream to the exhaust ports, preventing direct contact between particles and the mirror surface.
2Object-affected harmful factors
If gas flow rate is increased to remove fine particles, then mirror reflectance is maintained, but energy consumption increases
Solution Approach 1:
Different regions of the chamber are provided with different exhaust characteristics through strategically positioned exhaust ports. The first exhaust port handles the plasma generation region with higher gas flow to remove particles at the source, while the second exhaust port positioned opposite the mirror provides localized exhaust protection. This local quality differentiation allows effective particle removal with optimized energy consumption in each region rather than uniformly high gas flow throughout the entire chamber.
Solution Approach 2:
The gas flow parameters are optimized for each exhaust port based on its position and function. By adjusting the gas flow rate and pressure parameters independently for different exhaust ports, the system achieves effective particle removal while minimizing overall energy consumption. The parameters are tuned to create sufficient flow to carry particles away from the mirror without excessive energy input.
3Object-affected harmful factors
If the second exhaust port is positioned close to the mirror, then particle removal efficiency is improved, but the magnetic field axis alignment is disrupted
Solution Approach 1:
The second exhaust port is positioned in a spatial dimension that provides effective particle removal without interfering with the magnetic field axis. By placing the exhaust port opposite the mirror and utilizing the three-dimensional space within the chamber, the design achieves particle removal functionality while maintaining the magnetic field axis alignment for EUV light generation. The spatial arrangement in multiple dimensions allows both functions to coexist without conflict.
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 configuration suppresses the decrease in reflectance of the EUV light concentrating mirror, thereby maintaining or enhancing the output of extreme ultraviolet light.
Implementation Method 1
a target substance to be turned into plasma with laser light radiated to a plasma generation region
Implementation Method 2
a target substance to be turned into plasma with laser light radiated to a plasma generation region
Implementation Method 3
a synchrotron radiation (SR) type apparatus using synchrotron radiation light
Implementation Method 4
a light concentrating mirror configured to concentrate extreme ultraviolet light generated by the turning of the target substance into plasma
Implementation Method 5
a magnetic field generation unit configured to generate a magnetic field including a magnetic field axis that crosses a light path of the extreme ultraviolet light
Data Source
AI summary
An extreme ultraviolet light generation apparatus may include a chamber causing a target substance to be turned into plasma with laser light, a light concentrating mirror concentrating extreme ultraviolet light generated by the turning of the target substance into plasma, a gas supply unit supplying gas into the chamber, a magnetic field generation unit generating a magnetic field including a magnetic field axis that crosses a light path of the extreme ultraviolet light, a first exhaust port arranged at a position through which the magnetic field axis passes in the chamber, a second exhaust port arranged at a position opposite to the light concentrating mirror in the chamber, and a gas exhaust amount adjustment unit adjusting a ratio between an exhaust amount of first exhaust gas exhausted from the first exhaust port and an exhaust amount of second exhaust gas exhausted from the second exhaust port.