Immersion Lithography Fluid Handling Structure Testing
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Solution Overview
Problem
Current methods for performance testing of fluid handling structures in immersion lithographic apparatuses are time-consuming and labor-intensive, failing to efficiently distinguish between defects caused by film pulling and bulldozing, and are prone to errors due to liquid leakage, which affects the yield of patterned substrates.
Innovation Solution
A method involving a test substrate with distinct resist and non-resist portions is used, where the fluid handling structure operates under specified parameters, and changes or residues on the substrate are detected using scatterometry or dosage sensor temperature analysis to assess liquid confinement and evaporation effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional performance testing methods are used for fluid handling structures, then comprehensive defect detection is possible, but the testing process is time-consuming and labor-intensive
Solution Approach 1:
The patent extracts the testing function from traditional comprehensive defect detection methods and implements a specialized quick test using scatterometry. This dedicated testing approach focuses specifically on detecting liquid leakage and meniscus formation, achieving comprehensive defect detection for fluid handling structures while significantly reducing testing time through automated optical measurement rather than manual inspection
Solution Approach 2:
The patent replaces manual, mechanical testing procedures with an automated optical measurement system using scatterometry. The quick test uses light scattering principles to detect liquid residues and meniscus formation automatically, eliminating time-consuming manual inspection while maintaining or improving detection accuracy for fluid handling defects
2Object-affected harmful factors
If gas flow of gas knife is increased to reduce film pulling, then film pulling defects are reduced, but bulldozing increases at the advancing side
Solution Approach 1:
The patent implements a feedback mechanism where the quick test measures actual liquid confinement performance and meniscus formation. This feedback information is used to optimize gas flow parameters dynamically, allowing the system to find the optimal balance between preventing film pulling and avoiding bulldozing defects based on real performance data rather than fixed parameters
Solution Approach 2:
The patent utilizes parameter changes in gas flow rate as a control variable to manage the trade-off between film pulling and bulldozing. By adjusting gas flow parameters based on quick test results and meniscus detection, the system can optimize liquid confinement to minimize both types of defects under different operating conditions
3Object-generated harmful factors
If gas flow of gas knife is reduced to reduce bulldozing, then bulldozing defects are reduced, but liquid confinement at the receding side deteriorates
Solution Approach 1:
The quick test provides feedback on liquid confinement effectiveness at both advancing and receding sides of the fluid handling structure. This information enables dynamic adjustment of gas flow parameters to maintain reliable liquid confinement while minimizing bulldozing defects, rather than using fixed low gas flow settings that compromise confinement
4Productivity
If scatterometry is used for quick testing, then testing speed increases, but the method must accurately distinguish between different defect types
Solution Approach 1:
The patent segments the defect detection process into distinct analysis components using scatterometry. By analyzing specific scattering patterns and angular distributions, the system can differentiate between various defect types (liquid residues, meniscus formation, surface contamination) while maintaining high testing speed through automated pattern recognition and classification algorithms
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 method provides quick and accurate performance testing of fluid handling structures, allowing for real-time adjustments to working parameters, reducing defects and improving yield by distinguishing between film pulling and bulldozing-related issues and quantifying liquid leakage effectively.
Implementation Method 1
The liquid may be confined to the immersion space by a fluid seal
Implementation Method 2
The fluid handling structure may create or use a flow of gas, for example to help in controlling the flow and/or the position of the liquid in the immersion space
Implementation Method 3
any variation (such as an edge of the substrate) or irregularity on the surface of the substrate such as a change in the contact angle which the immersion liquid makes with the surface of the substrate may act as a meniscus pinning feature as the immersion fluid passes over it
Implementation Method 4
the meniscus of the immersion fluid between the surface of the substrate and the fluid handling structure is stretched
Implementation Method 5
As the substrate moves, the advancing portion of the fluid handling structure collides with the droplet of immersion fluid and the droplet is pushed forwards by the fluid handling structure
Implementation Method 6
detecting change to and/or residue on the first portion as a result of liquid being left behind on the first portion during the moving
Implementation Method 7
allowing at least partial evaporation of any immersion liquid on the dosage sensor thereby to induce a cooling load on the dosage sensor
Data Source
AI summary
A method of performance testing working parameters of a fluid handing structure in an immersion lithographic apparatus, the method including: placing a test substrate having an upper surface with a first portion with a resist defining the upper surface and a second portion with a material different from the resist defining the rest of the upper surface on a table in the immersion lithographic apparatus, confining liquid on a region of an upper surface of the table and/or the upper surface of the test substrate by operating the fluid handing structure using the associated working parameters, moving the table such that the region moves from the second portion to the first portion, and detecting change to and/or residue on the first portion as a result of liquid being left behind on the first portion during the moving.