Slurry parameters effect on Chemical Mechanical Planarisation (CMP) of deposited silver (Ag) on chips

Ag-deposited chips composed of electrodes, which are spaced apart by photoresist, are polished by Chemical-Mechanical Planarisation (CMP). We optimise the polishing process parameters including processing pressure, rotating speed, slurry supplying rate, etc., and examine the effect of some slurry parameters such as abrasives, oxidisers, corrosives, complexing agents and surfactants and get optimum Ag CMP slurry with high Material Removal Rate (MRR) and low average roughness (Ra). Low vertical distance between Ag and photoresist is obtained by optimising metal Ag MRR and controlling polishing end-point exactly. CMP mechanism and relationship between surface defects and additives structures are elementary discussed too.