EUV Light Source Nozzle Protection via Magnetic Field Extraction
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Solution Overview
Problem
In extreme ultraviolet light source apparatuses using the LPP system, debris from plasma generation damages optical elements, and existing magnetic field trapping methods can sputter the target nozzle, affecting position stability and contaminating other components.
Innovation Solution
A magnetic field generator creates a magnetic field to converge charged particles towards a collector, while the target nozzle is positioned outside the convergence region, and a target collector is placed opposite to the nozzle to collect residual targets, reducing collisions and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a magnetic field generator is used to converge charged particles toward the direction of the magnetic field, then charged particles can be effectively trapped and directed away from optical elements, but the target nozzle located on the magnetic field axis may be sputtered by fast ion debris, affecting position stability and contaminating other components
Solution Approach 1:
The target nozzle is extracted from the magnetic field convergence region and repositioned outside this region. This separation removes the nozzle from the harmful effects of sputtering by fast ion debris while maintaining its function of supplying target material to the plasma generation point, thereby resolving the contradiction between protecting optical elements and maintaining nozzle reliability
Solution Approach 2:
A charged particle collector is introduced as an intermediary component between the magnetic field convergence region and the target nozzle. This collector receives and accumulates charged particles that are converged by the magnetic field, preventing them from reaching and damaging the target nozzle, thus protecting position stability while still trapping particles away from optical elements
2Productivity
If the target nozzle is positioned inside the convergence region to facilitate target supply, then target material can be efficiently delivered to the plasma region, but the nozzle will be damaged by sputtering from fast ion debris
Solution Approach 1:
The target nozzle is extracted from the convergence region where fast ion debris causes sputtering damage. By repositioning the nozzle outside this region while maintaining its alignment with the plasma generation point, the system maintains efficient target material supply productivity while eliminating the harmful sputtering effect
Solution Approach 2:
The charged particle collector serves as an intermediary that intercepts fast ion debris before it can reach the target nozzle. This collector accumulates the charged particles in a controlled manner, protecting the nozzle from sputtering damage while allowing the nozzle to remain in an optimal position for target supply efficiency
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 effectively prevents nozzle deterioration and contamination of optical elements, maintaining position stability and ensuring the integrity of the EUV light source apparatus.
Implementation Method 1
a magnetic field generator which generates a magnetic field region around a direction of the magnetic field passing through a plasma region
Implementation Method 2
converges charged particles including ion emitted from the plasma region toward the direction of the magnetic field
Implementation Method 3
a target material supplied inside a vacuum chamber is irradiated with a laser light to be ionized and thus generate plasma
Implementation Method 4
irradiating a target with a laser light
Implementation Method 5
The multilayer coating has a high reflectance ratio (of about 60% to 70%) for the EUV light with a 13.5 nm wavelength
Data Source
AI summary
An extreme ultraviolet light source apparatus has a magnetic field generator which generates a magnetic field region around a direction of the magnetic field passing through a plasma region in which a plasma is to be generated and converges charged particles including ion emitted from the plasma region toward the direction of the magnetic field, a first charged particle collector (receiver) mounted at both sides of an axis of the magnetic field in the magnetic field region in order to collect (receive) the charged particles converged by the magnetic field, a target supply unit supplying a target from a nozzle located outside a converging region in which the charged particles are to be converged inside the magnetic field region in an extreme ultraviolet light generating chamber, and a target collector located at a position opposite to the nozzle, the target retrieval portion retrieving a residual target which does not contribute to generation of the plasma.