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During wet processing, semiconductor devices are repeatedly dipped, immersed, or sprayed with solutions to minimize the risk of contamination. Even when these cleaning steps are performed, the primary reason for device failure is ionic, organic, and metallic contamination of the wafer surface. As device features continue to shrink, ensuring the purity of acids, bases, and solvents used in the manufacture process will remain critical.
Chemical filters not only need to remove particulate contamination, but must also be free of dissolved contaminants. Dissolved contaminants are materials that have leached or extracted from components in the chemical delivery system. A filter that is not thermally or chemically compatible with the process chemical or has not been cleaned properly during the manufacturing process can leach organic and inorganic extractables onto the wafer surface. As a result wafer defectivity can increase and process yields decrease.
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