EUV Collector Debris Mitigation via Gas Flow Guiding
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Solution Overview
Problem
In EUV lithographic systems, debris from target materials like tin accumulates on EUV collectors and inner vessel walls, leading to reduced efficiency, lifetime, and increased downtime due to contamination, which is difficult to clean and affects the quality of produced EUV radiation.
Innovation Solution
A gas flow guiding device and debris mitigation system are implemented within the EUV vessel, using a showerhead with nozzles to introduce gas and an asymmetric or symmetric exhaust configuration to direct gas flows away from the EUV collector, preventing debris deposition on inner vessel walls and collectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas flow is introduced to protect inner vessel walls from debris, then debris accumulation is reduced, but device complexity increases due to additional gas supply systems and exhaust configurations
Solution Approach 1:
The gas supply system is segmented into multiple independent gas inlets positioned at different locations within the vessel. Each inlet can be controlled separately to create localized gas flows that protect specific regions of the inner vessel wall and collector, allowing targeted protection without requiring a complex system-wide approach.
Solution Approach 2:
A guiding device is introduced as an intermediary element within the gas flow path. This device actively directs the gas flow to follow specific trajectories that maximize protection of the collector and inner vessel walls while minimizing gas consumption and system complexity. The guiding device mediates between the gas source and the protection target, optimizing the flow pattern.
2Reliability
If asymmetric exhaust configuration is used to direct gas flow away from collector, then debris protection is improved, but manufacturing precision requirements increase
Solution Approach 1:
The exhaust system is deliberately configured in an asymmetric manner, with exhaust outlets positioned at non-uniform locations and angles relative to the vessel center. This asymmetric configuration naturally directs gas flows away from the collector in multiple regions simultaneously, providing comprehensive debris protection. The asymmetry is designed to match the debris generation patterns and vessel geometry rather than requiring perfect symmetric alignment.
3Area of stationary object
If multiple gas inlets are added to protect different vessel regions, then coverage is improved, but device complexity increases
Solution Approach 1:
The gas supply system is designed with multi-functionality, where the same gas inlet structure serves multiple purposes: protecting the inner vessel wall from debris, directing flows to specific regions, and working in conjunction with the guiding device to optimize overall flow patterns. This universal design reduces the need for separate dedicated systems for each protection function.
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 debris accumulation, maintaining the efficiency and longevity of EUV collectors by creating a barrier against debris, thereby minimizing downtime and ensuring consistent EUV radiation quality.
Implementation Method 1
A gas flow guiding device and debris mitigation system are implemented within the EUV vessel, using a showerhead with nozzles to introduce gas and an asymmetric or symmetric exhaust configuration to direct gas flows away from the EUV collector
Implementation Method 2
An EUV source may generate EUV radiation by illuminating target material such as tin (Sn) with radiation from a high power laser radiation source. A result of illuminating target material with laser radiation is the generation of laser produced plasma (LPP), which may then emit EUV radiation
Data Source
AI summary
An extreme ultraviolet radiation (EUV) source, including: a vessel having an inner vessel wall and an intermediate focus (IF) region; an EUV collector disposed inside the vessel, the EUV collector including a reflective surface configured to reflect EUV radiation toward the intermediate focus region, the reflective surface configured to directionally face the IF region of the vessel; a showerhead disposed along at least a portion of the inner vessel wall, the showerhead including a plurality of nozzles configured to introduce gas into the vessel; and one or more exhausts configured to remove gas introduced into the vessel, the one or more exhausts being oriented along at least a portion of the inner vessel wall so that the gas is caused to flow away from the EUV collector.