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Recent innovations in device design, including FinFETs and metal gate technologies, have required similar innovation in lithographic materials and process development. Complex processes such as double patterning and multilayer imaging require new and novel material chemistries to meet the rigorous defect level requirements for successful yield. To address these complex processes, new materials for multilayer imaging, including spin-on hardmask layers and thick carbon underlayers, have been introduced. These two types of materials have different roles in the multilayer imaging scheme, and likewise the chemistries that are used in these materials are different. To evaluate the wide variety of materials, it is necessary to be able to install them on a coater-track quickly and efficiently and to ensure that the chosen filter uses the best available filtration settings to provide the best-performing material. Typically end users of point-of-use filters will install a new filter, which will be primed with the best-known method, and purge chemical until a defect baseline is reached. This study examines the interaction between a spin-on hardmask chemistry and membrane materials, examining decreasing pore size and the differential pressure increases. Under these conditions, known issues with particles, microbubbles, or oddly timed defect excursions should be able to be avoided with the proper selection and start-up of the filter. An Entegris IntelliGen® Mini dispense system with Impact® 2 filters was used to test different filtration settings on various filtration membranes and determine the best settings for each membrane type. These pumps have the capability to control differential pressure across the filter based upon its operating parameters. Results of this investigation will show that for the spin-on hardmask material, optimizing differential pressure across the filter by adjusting the IntelliGen® Mini operating parameters will ultimately reduce blanket coat defect levels. As well, reducing pore size yields a greater impact to reduction of post-coat defect counts.
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