EUV Lithography Pellicle Rupture Detection via Distributed Sensors
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Solution Overview
Problem
Existing methods for detecting pellicle breakage in extreme ultraviolet lithography systems are limited to the EUV exposure stage, leading to potential contamination of subsequent stages if the break occurs earlier in the process, and require lengthy cleanup procedures when detected.
Innovation Solution
Incorporating sensors at multiple stages of the extreme ultraviolet lithography system, including particle counters and acoustic sensors, to detect pellicle breakage earlier and prevent contamination by triggering corrective actions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors are installed only at the EUV exposure stage, then detection is simpler, but pellicle breakage occurring at earlier stages cannot be detected, leading to system contamination
Solution Approach 1:
The detection system is segmented into multiple independent sensor units distributed across different stages (load lock chamber, transfer path, exposure chamber). Each sensor independently monitors for particles in its local zone, allowing comprehensive coverage without requiring a single complex centralized detection system.
Solution Approach 2:
Particle counters and acoustic sensors act as intermediary detection devices that indirectly detect pellicle breakage by sensing particles or acoustic signals generated when the pellicle breaks, rather than directly monitoring the pellicle itself throughout the system.
2Productivity
If cleanup procedures are initiated only after pellicle breakage is detected at the exposure stage, then the detection method is simpler, but system downtime and contamination spread increase
Solution Approach 1:
The system performs preliminary detection at multiple stages before the exposure stage. When particles are detected by sensors in the load lock chamber or transfer path, the system immediately initiates cleanup procedures, preventing contamination from spreading to additional stages and reducing overall downtime.
Solution Approach 2:
The distributed sensor network provides continuous feedback about particle presence at different stages. This feedback enables real-time monitoring and immediate response to pellicle breakage events, allowing the system to adapt its cleanup procedures based on the location and severity of contamination.
3Measurement precision
If multiple sensors are deployed across all stages, then early detection and contamination localization are improved, but system complexity and cost increase
Solution Approach 1:
Each sensor is designed to perform a specific local function: particle counters detect particles in their immediate vicinity, while acoustic sensors detect breakage sounds. This local specialization allows each component to be simple and effective, while the collection of local detections provides comprehensive system-wide monitoring capability.
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
Enables early detection of pellicle breakage, localizes contamination, and reduces the time required to bring the system back online by allowing for immediate corrective actions across all stages, thereby minimizing defects and downtime.
Implementation Method 1
A particle counter is located at or adjacent to the in-vacuum robot (IVR) and measures a number of particles
Implementation Method 2
In an embodiment, the at least one sensor includes an acoustic wave sensor
Data Source
AI summary
An extreme ultraviolet (EUV) lithography system includes an extreme ultraviolet (EUV) radiation source to emit EUV radiation, a collector for collecting the EUV radiation and focusing the EUV radiation, a reticle stage for supporting a reticle including a pellicle for exposure to the EUV radiation, and at least one sensor configured to detect particles generated due to breakage of the pellicle.