Carbon Quantifying Cell for Ultrapure Water Analysis
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Solution Overview
Problem
Conventional TOC analyzers are unable to identify organic molecules in ultrapure water (UPW) due to their inability to differentiate between Faradaic current and background charging current, making it difficult to detect ppb levels of organic compounds in low or no electrolyte conditions, which is crucial for semiconductor and pharmaceutical industries.
Innovation Solution
A carbon quantifying cell with electrodes made of titanium dioxide (TiO2) or boron-doped diamond (BDD) materials that applies an electrical oxidization, polarization, and/or adsorption program across electrodes to measure impedance and quantify carbon materials in UPW, allowing for the detection and speciation of organic compounds without the need for electrolytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional TOC analyzers are used to measure carbon in UPW, then the measurement can be performed, but the analyzers cannot identify organic molecules or differentiate between Faradaic current and background charging current
Solution Approach 1:
The patent segments the measurement process into multiple distinct phases: polarization phase (to establish electrochemical equilibrium), oxidation phase (to generate Faradaic current from organic molecules), and measurement phase (to measure impedance). This segmentation allows differentiation between background charging current and Faradaic current by measuring at different time points, thereby enabling both accurate carbon measurement and organic molecule identification
Solution Approach 2:
The patent applies a preliminary polarization step before the oxidation measurement. During this preliminary action, the electrode is polarized at a high potential for a predetermined time to establish electrochemical equilibrium and minimize double-layer charging effects. This preliminary action ensures that subsequent measurements primarily reflect Faradaic current from organic molecules rather than background charging current, resolving the contradiction between measurement accuracy and information loss
2Quantity of substance
If conventional TOC analyzers measure CO2 production from oxidation, then total organic carbon can be quantified, but the specific organic molecules cannot be identified
Solution Approach 1:
The patent employs dynamic impedance measurement during the oxidation process, continuously monitoring changes in electrical impedance as organic molecules are oxidized. By analyzing the temporal dynamics of the impedance change and comparing it against known oxidation rates of different organic compounds, the system can identify specific organic molecules while simultaneously quantifying total organic carbon, thus resolving the contradiction between quantity measurement and speciation information
3Manufacturing precision
If UPW is used in semiconductor manufacturing with decreasing feature sizes, then manufacturing precision improves, but the tolerance for impurities decreases making detection more difficult
Solution Approach 1:
The patent replaces conventional mechanical/chemical measurement methods with an electrical field-based detection system. By applying electrical potentials and measuring impedance changes, the system can detect trace organic impurities at extremely low concentrations (parts per billion) without requiring complex sample preparation or chemical reagents. This electrical substitution enables detection sensitivity that matches the increasing manufacturing precision requirements for smaller semiconductor features
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 accurate detection and quantification of organic compounds at ppb levels in UPW, providing online speciation capabilities and identifying interfering materials, thus improving the quality control in semiconductor and pharmaceutical manufacturing processes.
Implementation Method 1
place an electrical oxidization, polarization, and/or adsorption program across the two or more electrodes and at least partially oxidize carbon materials in the fluid
Implementation Method 2
place an electrical oxidization, polarization, and/or adsorption program across the two or more electrodes
Implementation Method 3
place an electrical oxidization, polarization, and/or adsorption program across the two or more electrodes
Implementation Method 4
measuring a resulting AC current across the two or more electrodes, wherein a ratio of amplitudes and a phase angle difference provides information for calculating a fluid impedance
Data Source
AI summary
A carbon quantifying cell configured to receive a fluid is provided, including two or more electrodes positioned at least partially in the fluid, and meter electronics configured to place an electrical oxidization, polarization, and/or adsorption program across the two or more electrodes and at least partially oxidize carbon materials in the fluid, apply an AC voltage of a predetermined amplitude across the two or more electrodes, measuring the resulting AC current across the two or more electrodes, wherein a ratio of amplitudes and a phase angle difference provides information for calculating a fluid impedance, receive an electrical response of the fluid to the electrical oxidization, polarization, and/or adsorption program, quantify the carbon materials in the fluid using the electrical response, and detect interfering materials in the fluid using the fluid impedance.