Liquid-Free Sample Trap for Airborne Molecular Contaminants
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Solution Overview
Problem
Current methods for measuring parts-per-trillion level acidic and basic airborne molecular contaminants in semiconductor photolithography are limited by inconsistent data, high detection limits, and require lengthy sample durations, with existing liquid-based traps facing issues of evaporative losses, partial dissociation of weak acids and bases, and handling challenges.
Innovation Solution
A liquid-free sample trap using a rigid sintered hydrophilic material, functionalized with basic or acidic species, which captures trace levels of acidic and basic airborne molecular contaminants in a gas stream within a shorter sampling period of 4-6 hours, achieving parts-per-quadrillion detection limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid-based sample traps (impingers) are used to capture airborne molecular contaminants, then soluble acidic and basic AMC can be captured, but evaporative losses occur and handling becomes challenging
Solution Approach 1:
The patent extracts the liquid component from the sample trap system, transitioning from liquid-based impingers to a liquid-free solid absorbent trap. This eliminates evaporative losses and handling challenges associated with liquids while maintaining the contaminant capture function through solid-phase absorption materials.
Solution Approach 2:
The patent changes the physical state parameter of the absorbent material from liquid to solid. By using a solid absorbent trap instead of liquid impingers, the system achieves the same contaminant capture function while eliminating the harmful effects of evaporative losses and liquid handling difficulties.
2Reliability
If liquid-based impingers are used for sampling, then acidic and basic AMC can be captured, but detection limits remain high and data consistency is poor
Solution Approach 1:
The patent employs disposable solid absorbent traps that are pre-conditioned and sealed until use. These single-use traps eliminate cross-contamination between samples and ensure consistent performance, achieving parts-per-quadrillion detection limits through standardized, disposable sampling units rather than reusable liquid impingers.
3Ease of operation
If proprietary solid state solutions are used, then liquid handling is improved, but preparation becomes complex and background signals increase
Solution Approach 1:
The patent segments the sampling system into pre-prepared, sealed, disposable trap units that require no field preparation. Each trap is independently conditioned and sealed, eliminating complex preparation procedures while maintaining simple operation. The traps are ready-to-use upon opening, achieving ease of operation without preparation complexity.
4Productivity
If standard impingers are used for sampling, then continuous measurement is possible, but sample duration becomes excessively long (24-72 hours)
Solution Approach 1:
The patent changes the absorption kinetics by using solid-phase absorbents with high surface area and optimized pore structures. This enables significantly faster contaminant uptake rates compared to liquid impingers, reducing sampling time from 24-72 hours to 4-8 hours while achieving the same detection sensitivity and data quality.
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 liquid-free trap provides consistent and accurate measurement of trace contaminants, exceeding the detection limits required for semiconductor industry standards, with improved handling and reduced contamination risks, enabling real-time monitoring and analysis within a single work shift.
Implementation Method 1
a liquid-free trap for trace levels of an acidic or basic airborne molecular contaminant in a gas... a rigid sintered hydrophilic material... for trapping airborne contaminants
Data Source
Figure 1A~1B
Figure 1C
Figure 1D
AI summary
Described herein are liquid-free traps for trace levels of an acidic or basic airborne molecular contaminant in a gas. In one version of the invention described herein, the liquid- free trap comprises a housing, comprising an inlet and an outlet; a flow path between the inlet and the outlet; and a rigid sintered hydrophilic material situated in the flow path between the inlet and the outlet and sealed in the housing. The rigid sintered hydrophilic material is functionalized with from about 0.05 molar milliequivalents to about 10 molar milliequivalents of a basic species for trapping an acidic airborne molecular contaminant in the gas or from about 0.05 molar milliequivalents to about 10 molar milliequivalents of an acidic species for trapping a basic airborne molecular contaminant in the gas. Methods of using the liquid-free traps to detect or measure trace levels of an acidic or basic airborne molecular contaminant are also described.