Profile temperature measurement for quality assurance in wafer production
Assuring the quality of manufacturing processes is crucial for chip yield in the semiconductor industry. In wafer coating, miniature thermocouples are used to ensure uniform coating at temperatures of 700°C. The challenge lies in tracking the processes with as many sensors as possible yet without any noticeable effects. RÖSSEL-Messtechnik has developed a test wafer that can be equipped with almost any number of sensors and also used in a vacuum chamber. The sensors are attached without adhesive and can be removed and recalibrated without causing any damage, ensuring maximum process quality paired with resource and cost savings.
The challenge
Coating processes on the wafer take place at temperatures up to 700°C. Sheathed thermocouples smaller than 0.5mm in diameter were therefore required to monitor temperatures. If possible, the process parameters needed to be recorded on the product to be coated (wafer) and checked against the measured values in the system. The main challenge was in temporarily mechanically attaching the thermocouples to the wafer without destroying it with subsequent removal. This step was unavoidable as the sensors needed to be removed from the wafer for calibration. Calibration with the sensors attached is unfortunately not possible.
The solution
RÖSSEL-Messtechnik developed a test wafer for the customer that permitted almost any number of sheathed thermocouples to be temporarily attached. Instead of adhesives, the same material used to coat the wafer was used to attach the thermocouples. This offered several advantages: 1. Adhesive-free application permits use in a vacuum environment. 2. Direct transfer to the process is possible. 3. The sensors can be removed without damage using a suitable process and can therefore be recalibrated and reused.
The advantage
Profile temperature measurement with the test wafer from RÖSSEL-Messtechnik offers customers the highest accuracy for process measurement values. The results are reproducible and reliable, improving the yield and quality of wafers as a result. The product allows customers to gain system-specific information about their process and optimize their coating processes with pinpoint accuracy.
Thanks to the ability to remove them without causing any damage, sensors from RÖSSEL-Messtechnik can be recalibrated and reused both on the same wafer and on others. After special cleaning procedures, the sensors can also be used in other coating processes. The ability to reuse the sensors saves the environment and resources.
This principle can be used for different furnace types and wafer sizes.
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As a leading manufacturer of temperature measuring technology for industrial and research purposes, we meet the strictest production standards. With internationally recognized approvals and calibrations, we offer quality you can rely on around the globe.
