To improve the surface quality after chemical mechanical polishing (CMP) of copper interconnects,appropriate surfactants need to be introduced into the slurry to improve the stability of the abrasive as well as the surface roughness of the copper after CMP.The effects of three anionic surfactants of ammonium dodecyl sulfate (ADSA),fatty alcohol polyoxyethylene ether ammonium sulfate (AESA) and linear alkyl benzene sulfonic acid (LABSA),and the composite surfactant of nonionic surfactant fatty alcohol polyoxyethylene ether (AEO-9) and anionic surfactant LABSA,on the slurry and polishing performance of Ta barrier layer were investigated.The surface tension,contact angle,large particle count,particle size distribution and copper surface roughness were characterized by contact angle measuring instrument,nanoparticle size analyzer,scanning electron microscope and atomic force microscope,and the action mechanism of the composite surfactant was analyzed.The results show that due to the linear chain structure of LABSA,the wettability and dispersion of the slurry after adding LABSA are the best and the roughness of the polished copper surface is the lowest.Compared with the single LABSA,the wettability,dispersion and stability of the slurry and surface roughness of copper after CMP are improved with the addition of composite surfactant.The performance of slurry with composite surfactant composed of 0.1% LABSA+0.1% AEO-9 is the best,and the roughness of the polished copper surface decreases to 0.7 nm.