There has been an increasing demand on filtration technology to enhance material purity in semiconductor unit processes. Many efforts to improve filtration have focused on establishing retention ratings using various particulate contaminants. While this is an important parameter to understand particle removal, it is equally important to understand the fundamental interactions between photochemicals and filters. As materials change and the smallest defects become even more challenging to detect, new filter screening methodologies are needed to address the most stringent defect targets.
In this paper, a novel filter screening metrology is introduced to identify optimized filtration candidates for specific defect sources and improve defectivity in Si hardmask materials. Results and possible mechanisms of defect reduction will be discussed.