| Analysis of Metals in Ultrapure water |
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학술지명 한국분석과학회
저자 한승철,이은정,장현지,유혜원,이종찬,소웅
발표일 2024-05-23
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The semiconductor industry requires a vast quantity of ultrapure water to produce to produce image sensors, wafers, and semiconductors. Ultrapure water is employed during manufacturing to wash the products and is also consumed to formulate fine chemicals and gases. Major foundry companies are continually striving to enhance the quality of ultrapure water, while also maintaining its quality, as the presence of impurity in the ultrapure water can induce serious defects in the products. The metals contents of ultrapure water for semiconductor purposes varies considerably between companies and production processes, with typically below 1 ng per liter. The International Roadmap for Devices and Systems(IRDS), operated by the Institute of Electrical and Electronics Engineers(IEEE), suggests that the metal content of ultrapure water for image sensor manufacturing purposes should be below 0.05 ng per liter. Trace metal analysis is typically conducted using an inductively coupled mass spectrometer (ICP-MS) or tandem mass spectrometer (ICP-MS/MS). Recently developed ICP-MS has sufficient sensitivity and resolution to analyze ultrapure water. However, most users have poor experimental environments, unproven tools, and inappropriate procedure to perform below parts per trillion level of analysis. Such a low level of analysis is extremely challenging and requires sophisticated procedures and a clean environment. The analysis cannot be conducted without strict contamination control. All bottles, chemicals, pipettes, gloves, and other tools used in the analysis must be tested and confirmed before use. The analysis is often performed in a clean room to prevent airborne molecular contamination during the analysis procedure. Trace metals exist everywhere and readily leach from the environment. Consequently, any contact with ultrapure water samples including sample bottles and injection lines should be checked and carefully managed. After comprehensive review, analysis of 20 metals was |