Cross-contamination control of new materials with minimum number of cleaning apparatuses

We examined the cross-contamination of Co, a newly introduced metal, by measuring the concentration of Co that dissolved into cleaning and wet-process solutions and the concentration of Co that adsorbed on Si surfaces immersed in the solutions. We identified an optimized line-up of cleaning and wet-process equipment that can control Co cross-contamination with the minimum amount of cleaning and wet-process apparatus.