Removal of Backside Particles by a Single Wafer Megasonic System

Abstract

Single wafer megasonics were used to remove backside particle contamination resulting from vacuum chucks and chambers. Process evaluation was done using blanket wafer experiments with Si3N4 particles. To increase the difficulty of the particle removal test vehicle, aged contaminated wafers were used. The impact of film type, megasonic power, process chemicals and etch amount were investigated. The impact of performing a backside megasonic clean prior to the lithography process was shown