Guide for Determining the Quality of Ion Exchange Resin Used in Polish Applications of Ultrapure Water System
The quality of the final-polish ion exchange (IX) resin is critical to the performance of ultrapure water systems used in advanced semiconductor facilities. Contaminants leaching from the resin, particularly particle precursors, are very difficult to remove with filtration, including ultrafilters.
Studies conducted by the International Roadmap for Devices and Systems (IRDS) in 2020 and 2021 have shown that extracts from semiconductor grade IX resins can result in particles on the wafers during a spin-coating process. SEMI C93 provides a method to measure the release of particles and particle precursors after installation of a virgin mixed IX resin system and to determine the volume of rinsing required to meet a cleanliness specification.
The two figures below are samples of data generated by CT Associates during the collaborative development of SEMI C93 with the SEMI UPW Task Force. The first shows the online rinse of several varieties of resin, as measured by a Kanomax FMT Scanning Threshold Particle Counter (STPC). The second shows the particle size distribution of a grab sample extracted from these resins, as analyzed by Liquid Nanoparticle Sizing (LNS). Both dynamic rinse and grab sample techniques, within the specification, can be used to measure resin contamination and clean-up.