ICP Light Source Direct Gas Injection for Faster Plasma Refill
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Solution Overview
Problem
Existing EUV light sources face limitations in brightness and reliability due to slow gas replenishment in the plasma confinement region, leading to performance constraints and increased self-absorption, especially in Z-pinch designs that rely on magnetic switches and electrode contact.
Innovation Solution
A direct feed gas injection system is implemented, where gas is injected directly into the plasma confinement region using a feed gas injector with multiple apertures, positioned close to the plasma boundary, to maintain a desired pressure ratio and reduce self-absorption, eliminating the need for gas migration and minimizing electrode contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas is supplied to the plasma confinement region through chamber pressure equalization, then the plasma region is replenished with feed gas, but the replenishment process is slow and leads to performance degradation and increased self-absorption
Solution Approach 1:
The gas supply system is segmented into multiple independent feed gas injectors, each with multiple apertures positioned at different locations within the plasma confinement region. This segmentation allows gas to be supplied through multiple parallel pathways simultaneously, dramatically increasing the replenishment speed compared to a single gas supply point.
Solution Approach 2:
The feed gas injectors are positioned with outputs within 1 cm (preferably within 1/2 cm) of the plasma confinement region boundary, transitioning from remote gas supply through pressure equalization to direct, localized gas injection at the plasma boundary. This spatial repositioning enables rapid gas replenishment directly at the plasma region.
2Stability of the object's composition
If higher gas pressure is maintained in the plasma confinement region to improve plasma stability, then plasma confinement is enhanced, but self-absorption of EUV light increases
Solution Approach 1:
The system creates a local quality gradient by maintaining higher pressure specifically within the plasma confinement region through direct gas injection, while the chamber pressure remains lower. The feed gas injectors are positioned to deliver gas precisely where needed (within 1 cm of the plasma boundary), creating a localized high-pressure zone that stabilizes plasma without increasing overall chamber pressure, thereby reducing self-absorption.
3Device complexity
If traditional gas supply methods are used, then the system structure is simple, but the EUV light source performance and brightness are limited
Solution Approach 1:
The feed gas injectors are pre-positioned with outputs close to the plasma confinement region boundary (within 1 cm or within 1/2 cm), and the apertures are pre-configured to direct gas flow into the plasma region. This preliminary positioning ensures that gas is immediately available when needed, enabling rapid plasma replenishment and sustained high brightness operation without waiting for pressure equalization.
4Ease of operation
If gas injection is delayed until after pinch expansion, then the system operation is simplified, but the plasma confinement region is not refilled at optimal times, reducing performance
Solution Approach 1:
The feed gas injectors are configured to operate in periodic cycles, injecting gas into the plasma confinement region at specific intervals that coincide with plasma pinch events. The system timing is synchronized so that gas injection occurs just before or during pinch expansion, ensuring the plasma region is refilled at optimal moments. This periodic injection pattern maintains reliable plasma confinement without requiring complex continuous control.
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 approach enhances EUV light source performance by increasing optical power and brightness, reducing operational costs, and extending the source's operational flexibility and stability, allowing higher repetition rates and reduced self-absorption.
Implementation Method 1
A magnetic core is positioned around the plasma confinement region and is configured to generate a plurality of plasma current loops that converges in the plasma confinement region during operation
Implementation Method 2
the feed gas injector provides a feed gas to the plasma confinement region that creates a differential pressure in the plasma confinement region
Implementation Method 3
Numerous commercial and academic applications have a need for high brightness light in the extreme ultra-violet (EUV) region of the spectrum
Implementation Method 4
Inductively Coupled Plasma Light Source with Direct Gas Injection
Data Source
AI summary
An ultraviolet light source with direct feed gas injection includes a chamber comprising a plasma confinement region and defining an aperture adjacent to the plasma confinement region that passes light generated by the plasma. A magnetic core is positioned around the plasma confinement region and is configured to generate a plurality of plasma current loops that converges in the plasma confinement region during operation. A feed gas injector is coupled to a gas port in the chamber and has an output that is positioned proximate to a boundary of the plasma confinement region so that the feed gas injector provides a feed gas to the plasma confinement region that creates a differential pressure in the plasma confinement region. A high voltage region is coupled to the plasma confinement region. An exhaust port is configured to be coupled to a pump that controls a pressure in the chamber.