Dual-function filtration to improve on-wafer defectivity performance for EUV applications

The progression of transistor miniaturization with mass production at the 3nm process node, the risk of contamination in photochemicals photoresists, spin-on carbon (SOC), and spin-on glass (SOG) becomes increasingly significant, highlighting the essential role of contamination control systems such as filters (particles) and purifiers (organics, metals, etc.) in mitigating threats to electrical microstructures on semiconductor chips. Entegris has been at the forefront of developing advanced chemical integrity and performance tools to minimize wafer defects and enhance product yields. Due to their widespread application, ultrahigh molecular weight polyethylene (UPE) membranes have become vital at the point of use (POU) filtration. Their ability to eliminate typical sources of defectivity, such as particles and aggregates in photoresist materials, is a testament to their effectiveness. This has traditionally been achieved through sieving filtration, utilizing the tiny pores of UPE filters and their exceptional photochemical compatibility. Furthermore, for particles at the molecular level, adsorption filtration (non-sieving filtration) has grown to become instrumental in significantly reducing wafer defects. This paper introduces our latest innovative, dual-functional filtration technology for photoresist POU filtration, which provides superior performance with both sieving and non-sieving filtration mechanisms. In addition to its advanced filtration capabilities, the new dual-functional filter demonstrates higher cleanliness standards than its predecessors, resulting in a notable reduction in wafer defectivity.