Recent advances and future developments in PVA brush scrubbing cleaning: A review

Abstract

As semiconductor integrated circuits (SICs) have been developed to scale down to obtain higher integration and better performance, more chemical mechanical polishing (CMP) steps make post-CMP cleaning more challenging. Polyvinyl alcohol (PVA) brush scrubbing dominates the post-CMP cleaning process due to its flexibility, single wafer processing, and low cost of ownership (COO). For recent two decades, researchers have been continuously attempting to improve the cleaning performance of PVA brush scrubbing to meet increasingly challenging requirements of post-CMP cleaning, and an enormous quantity of literature is available. This paper aims to review and discuss the current status of PVA brush scrubbing, comment on current challenges, and forecast the future development trend based on the overall observation, thereby providing a deeper understanding of this technology for both academics and practicing engineers. Initially, we compendiously summarize the source of contamination and mechanisms of particle adhesion and removal. The research status of PVA brush scrubbing is then outlined and analyzed in terms of both mechanical and chemical influencing factors from the cleaning process and cleaning targets. Finally, we discuss the existing challenges of PVA brush scrubbing in integrating other cleaning methods and possible future development with emerging potential analytical technologies.