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2026/08/19Clicks：7
In semiconductor wafer fabs, gas detection systems often need to measure hazardous gases at very low concentrations. When the target concentration is at the PPB level, the sampling tube itself can become an important part of the measurement system.
For a semiconductor wafer fab gas detection project, the required gases were NH₃, HF and HCl, with strict requirements for detection response and concentration variation before and after the tubing was connected.
After application testing, CJan Fluid Technology Co., Ltd. provided PFA tubing manufactured with 231SH imported PFA raw material. The tubing passed the customer's compliance testing and met the project requirements.
The end application is environmental gas monitoring inside a semiconductor wafer fabrication facility.
The system is designed to detect:
The challenge is not simply transporting these gases from the sampling point to the detection instrument. At PPB-level concentrations, the interaction between the gas and the tubing material can affect the measured concentration.
Therefore, the customer specifically required a tubing material with low adsorption characteristics and stable performance during gas sampling.
| Item | Requirement |
|---|---|
| Industry | Semiconductor |
| Application | Wafer Fab Environmental Gas Detection |
| Target Gases | NH₃ / HF / HCl |
| Reference Concentration | 20 PPB |
| Detection Requirement | ≥10 PPB within 20 minutes |
| Pump | No additional sampling pump |
| Sampling Rate | Based on the test equipment |
| HF / HCl Difference Before & After Tubing | ≤0.1 PPB |
| NH₃ Difference Before & After Tubing | ≤15 PPB |
| Main Tubing Requirement | Low adsorption |
| Recommended Material | PFA |
| Raw Material | 231SH imported PFA resin |
At higher gas concentrations, a small amount of interaction between the gas and tubing wall may have a relatively limited impact.
PPB-level detection is different.
When the target concentration is only a few PPB or tens of PPB, even a small change during sampling can become significant to the final measurement.
For this reason, gas sampling tubing needs to be evaluated for:
This is particularly important for gases such as HF, HCl and NH₃.
Based on the customer's requirements, CJan recommended PFA tubing manufactured using 231SH imported PFA raw material.
PFA is a fluoropolymer widely used in semiconductor and high-purity applications because of its chemical resistance, cleanliness, and stable material properties.
For this project, the key reason for selecting PFA was its suitability for a low-adsorption gas sampling application, which was then verified under the customer's actual test conditions.
For PPB-level gas detection, the tubing should introduce as little change as possible to the sampled gas.
PFA offers a relatively low-adsorption surface compared with many general-purpose tubing materials, making it a suitable candidate for trace-gas sampling applications.
However, actual adsorption behavior depends on the gas, concentration, humidity, tubing dimensions, surface condition, flow rate, and exposure time.
That is why application testing remains important.
HF and HCl are highly corrosive gases, while NH₃ also requires appropriate material compatibility.
PFA has excellent chemical resistance and is widely used in semiconductor chemical handling and high-purity fluid systems.
This provides a suitable material foundation for gas sampling applications involving aggressive chemical species.
The project required tubing suitable for a semiconductor wafer fab environment.
Using 231SH imported PFA raw material provides a controlled material basis for the tubing used in this application.
For semiconductor gas monitoring systems, material cleanliness can be just as important as chemical resistance.
Rather than relying only on theoretical material properties, the PFA tubing was tested under the customer's specified conditions.
The test involved:
20 PPB HF / HCl / NH₃
with the requirement that the detection instrument should reach:
≥10 PPB within 20 minutes.
The test was performed without an additional extraction pump, with the sampling rate determined by the testing equipment.
The tubing was also evaluated by comparing the gas concentration before and after connection to the tubing.
Customer requirements included:
HF / HCl:
Difference before and after tubing connection ≤0.1 PPB
NH₃:
Difference before and after tubing connection ≤15 PPB
The supplied PFA tubing passed the customer's compliance testing and met the required application criteria.
For ordinary industrial hose selection, material compatibility tables can often provide a good starting point.
For PPB-level gas detection, however, material selection alone may not be enough.
The actual result can also be affected by:
Therefore, for critical trace-gas applications, testing the complete sampling setup under actual operating conditions is recommended.
This project followed that approach: the PFA tubing was selected based on the application requirements and then verified through actual testing.
Depending on the specific gas and system design, PFA tubing can be considered for:
For each application, compatibility and adsorption performance should be evaluated according to the actual gas composition and sampling conditions.
When selecting tubing for a semiconductor gas monitoring system, several factors should be considered.
Confirm that the tubing material is suitable for the target gas.
For PPB-level detection, tubing adsorption can affect the measured concentration and response time.
The tubing should be appropriate for the cleanliness requirements of the monitoring system.
The flow rate directly affects gas residence time inside the tubing.
Longer tubing or smaller internal diameter can increase the interaction time between the gas and the tube wall.
For demanding applications, the best way to confirm suitability is to test the tubing under the actual operating conditions.
This project involved semiconductor wafer fab environmental gas detection, with NH₃, HF and HCl as the target gases.
The customer required:
20 PPB target concentration → ≥10 PPB detection within 20 minutes
and specified concentration differences before and after tubing connection of:
HF / HCl ≤0.1 PPB
NH₃ ≤15 PPB
Based on the application requirements, CJan Fluid Technology Co., Ltd. provided:
The tubing passed the customer's compliance testing and met the requirements of the application.
The project demonstrates an important point in trace-gas monitoring: the sampling tube should be treated as part of the measurement system, not simply as a connection component.
CJan Fluid Technology Co., Ltd. specializes in fluid transfer and connection solutions for demanding applications.
Our product range includes:
CJan serves customers in:
Semiconductor | Chemical | Pharmaceutical | Lithium Battery | Food & Beverage | New Energy
For special applications, CJan can evaluate hose and tubing selection according to the actual medium, concentration, temperature, pressure, flow rate, cleanliness requirements and installation conditions.
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