High-k metal gate poly opening polish at 28nm technology polish rate and selective study

A robust poly opening polish (POP) CMP for replacement metal gate (RMG) application has been developed to meet the criteria of High-k metal gate (HKMG) devices at 28nm technology node. From the previous performance of POP CMP, the uniformity and loading was an important factor of product with HKMG. The polish rate and selective of platen 2, which were key physical characters, was taken to study by recipe and film type tuning. As the results, the platen and head rotate speed (rpm) can influence the selective of SiN and oxide remove rate. In addition, the SiN remove rate was been changed by different slurry shelf life.