Concentration measurement
in the
semiconductor industry
in the
semiconductor industry
Concentration monitoring for semiconductor processes – for efficient production, stable processes, and highest quality.
Up to ±0.02 wt%
Real-time measurement
Maintenance-free
Kostensparend
Challenges in concentration measurement in semiconductor processes
In semiconductor manufacturing, the exact ratio of chemical concentrations is crucial, but traditional lab analyses often deliver results too late. With LiquiSonic® SensoTech enables reliable real-time monitoring that can be easily integrated into existing processes. The system delivers maintenance-free precise measurement data, thus enhancing process safety and efficiency.
Challenges
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Chemical concentrations not within target range
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Time-consuming lab analyses
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No immediate and reliable information on chemical composition
Solution: LiquiSonic®
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Clear monitoring with LiquiSonic®
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Immediate display of chemical concentration
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Seamless integration into existing systems
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Maintenance-free and without consumables
Your advantages
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Traceable and reliable measurement results
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Measurement results in real-time
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Completely maintenance-free sensors and chemical-resistant materials
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Easy integration into systems of any size and configuration
Our solution: The LiquiSonic® Measuring system
Monitor concentration in real-time
LiquiSonic® combines modern ultrasonic technology with temperature-compensated measurement to provide precise results for critical chemical mixtures in semiconductor manufacturing. Real-time monitoring ensures stable product quality, reduces deviations, and provides data for process optimizations. This reduces operating costs and chemical consumption while increasing process safety and efficiency.
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Ensure quality: Real-time monitoring guarantees precise results without deviations.
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Reduce costs: Optimized processes for maximum reliability and lower consumption.
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Increase efficiency: Higher product quality with reduced operating costs.
Technical details and specifications
Ultrasonic measuring principle
The speed of sound in liquids is directly related to the concentration of dissolved substances. High-precision time measurements enable an exact determination of the concentration.
Conductivity integration
In three-component systems, conductivity is used as a second physical parameter to clearly determine both concentrations.
Temperature compensation
Two PT1000 sensors integrated into the measuring cell provide automatic temperature compensation and thus precise measurements under all conditions. By directly capturing the process temperature, the speed of sound is corrected in real-time, improving stability and accuracy even with fluctuations.
Economic benefit
Real-time concentration measurement increases quality, efficiency, and reliability, while simultaneously reducing costs and resource consumption:
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Reduced operating costs through lower chemical consumption and fewer laboratory analyses
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Less waste and rework, as deviations can be detected and corrected immediately
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Stable product quality ensures competitiveness and reduces complaints
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More efficient processes through real-time data instead of delayed laboratory measurements
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Higher plant availability through maintenance-free sensors without consumables
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Process optimization through precise data leads to continuous improvement and better resource utilization
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Fast ROI thanks to savings in energy and operating costs
Technical specifications
Measurement accuracy | Up to ±0.02 wt% |
Temperature range | 5 °C to 60 °C |
Pressure range | Up to 4 bar |
Material & coating | PFA |
Digital transmission | Up to 1,000 m (more on request) |
Interfaces | 4-20 mA, Profibus, Ethernet, Modbus, Fieldbus, ... |
Protection class | IP65 |
Calibration | One-time factory calibration |
Maintenance | Completely maintenance-free |
Application examples
Typical chemical process steps and our process solutions used for cleaning and etching processes as well as special etching and development processes: For cleaning and etching processes as well as special etching and development processes:
SC-1 (APM)
NH4OH/H2O2
SC-2 (HPM)
HCI/H2O2
SPM (Piranha)
H2SO4/H2O2
Oxide removal (DHF)
HF
Oxide removal (BOE/BHF)
HF/NH4F
Si₃N₄ etching
H3PO4
Isotropic silicon etching
HF/HNO3
Anisotropic silicon etching (MEMS)
KOH/Si
TMAH/Si
Photoresist development
TMAH
Nitric acid / acetic acid
HNO3/CH3COOH
HF / HCl
HF/HCl
Success stories and references:
You can obtain detailed case studies and customer references from our sales team. Contact us for specific application examples from your industry.
The main advantages at a glance
Consistent quality
Real-time monitoring prevents deviations and ensures consistent product quality.
Cost savings
Less chemical consumption and lower operating costs through optimized processes.
Highest efficiency
Real-time data enables faster decisions and optimized processes.
Maintenance-free
Sensors are chemical-resistant and require no consumables.
Frequently asked questions
SensoTech GmbH is a leading company in the field of process measurement technology based in Barleben, near Magdeburg, Germany. We develop and produce innovative solutions for monitoring and optimizing industrial processes. Our specialization lies in the precise measurement of concentrations, densities, and other parameters in liquids – in real-time and directly during the process.
Unlike optical methods, which are influenced by color or turbidity, conductivity-based methods, which are sensitive to electrical conductivity, or density-based methods, which can be disturbed by temperature or gas bubbles, our ultrasonic method is independent of these influences.
The LiquiSonic® measurement technology also contains no moving parts or components that can wear out or be consumed. Therefore, after installation, the measurement system is completely maintenance-free and drift-free.
The sensors offer digital signal transmission up to 1000 m and enable continuous inline measurement without sampling.
Our system uses ultrasonic transit time measurement to determine the speed of sound in the liquid. This speed of sound directly correlates with the chemical concentration and enables measurement accuracies of up to ±0.02 wt%. The integrated temperature compensation ensures stable results even with fluctuating process conditions.
The system provides results in real-time. It performs over 30 measurements per second. Based on these measurements, you receive an updated measurement value every second. This fast response time allows effective process control and early detection of deviations.
Since the speed of sound, like all other physical quantities, is influenced by temperature, all our LiquiSonic® sensors are equipped with high-precision temperature sensors. This allows the influence of temperature on the measurement to be directly compensated Therefore, there is no need to integrate additional temperature sensors.
Our semiconductor sensors operate reliably in a temperature range of 5 °C to 60 °C and pressures up to 4 bar.
Yes, by combining the speed of sound measurement with additional physical quantities (e.g., conductivity), multiple components can be determined simultaneously. This also allows monitoring of additional additives.
The system offers various digital interfaces (e.g., Profibus, Ethernet/IP, Foundation Fieldbus) as well as analog 4-20 mA outputs. The integration is seamless via standardized protocols.
The system is completely maintenance-free. There are no mechanical wear parts, seals, or optical windows that could be compromised. Regular calibration is not required - the sensors remain stable for years.
Related applications
Texture and etching baths
In etching baths, material layers are selectively removed to create desired surface structures.
PCB cleaning
The cleaning removes organic residues, particles, and oxides to ensure that the circuit traces can be processed reliably.
Pickling bath monitoring
Pickling baths dissolve oxides or impurities from metal surfaces and must be kept constantly within the correct concentration range.
Green liquor monitoring
Green liquor is a highly alkaline byproduct in paper production, and its concentration must be monitored for stable subsequent processes.
Acid concentration measurement
The precise determination of concentrations in aggressive chemicals is crucial to allow reactions to proceed in a controlled and safe manner.
Gas scrubbers
In gas scrubbers or neutralization plants, pollutants are removed from exhaust air or liquids, requiring precise control of the chemicals used.