Filtration study with nylon membrane for metal removal performance improvement

Abstract

Lifetime extension of metal removal application utilizing Nylon 6,6 membrane was investigated with point of use (POU) filters. In this study, new samples which applied Nylon 6,6 membrane with different membrane properties including thickness, area and volume as well as ref. sample with standard membrane were prepared to investigate parameters which are expected to affect the metal removal capacity with breakthrough testing to analyze of metal removal effectiveness. As a result, it was found that the sample with thicker membrane leading to a larger membrane volume tended to show increased metal removal performance. Best correlation was seen with membrane volume (thickness × area) for metal removal performance. Data of flow dP(differential pressure), liquid particle count and initial cleanliness using metal extractions were also collected as fundamental filter performance. Lastly, we confirmed that these new samples showed lower flow dP and comparable cleanliness performance to ref. sample.Based on this study, we successfully developed a new Nylon filter which extends the metal removal lifetime while keeping comparable cleanliness and greater flow dP (differential pressure) performance using the same capsule format. These findings will be very useful in the development of next-generation filtration products, ultimately contributing toward reduced defectivity and increased yield within next-generation lithography processes.