Effect of process parameter on particle removal efficiency in brush scrubber cleaning

A brush scrubbing apparatus was developed for Post CMP cleaning process of 300mm wafer. Fluorescent particles with a size down to 100nm were used as the contaminated particles. The removal efficiency of fluorescent particle from Cu surface was calculated with the help of fluorescent microscope and Image Pro Plus software. The comparison of fluorescent image and SEM image showed that a single 100nm fluorescent particle could be observed by using fluorescent microscope. According to the results, the increasing of brush rotation speed, wafer rotation speed and cleaning time is helpful to improve the cleaning efficiency. Also we conclude that the edge area of the wafer is more difficult to clean than the center area. Keywords: Chemical mechanical polishing, Fluorescent particle, Brush scrubber cleaning, Particle removal efficiency, Apparatus.