Nano Filtration Using Polysulfone Membrane : CFM: Contamination Free Manufacturing

Defect control is imperative to leading-edge semiconductor industry. Nano filtration has been effective at reducing defects caused by particles and metal contamination. In this presentation, we focus on filters that consist of polysulfone (PSF) membrane and ion exchange membrane (IEM) for effective removal of particles and metal ions. In the real application case, either one filter containing dual layer membranes (PSF + IEM) or two separate filters (PSF filter + IEM filter) can be installed to remove both particles and metal ions from chemicals or water used in semiconductor manufacturing, depending on the process conditions and requirements. Polysulfone polymer membrane has a highly asymmetric structure that allows superior flow rate and fine particle retention. With optimal filter design, the best filters can remove particles down to 1 nm size while exhibiting a low pressure drop. The membrane in IEM typically has negatively charged functional groups on the surface. The leading IEM product can effectively remove >90% trace metal ions from solutions. This manuscript will give an overview of the issues at end users and discuss how advanced filtration technology help solve the issues and enable semiconductor manufacturing.