Study On Layer-by-layer Electrostatic Self-assembly Composite Abrasives Slurry And Its Silicon Wafer CMP Performance

Chemical mechanical polishing(CMP)technology is so far almost the only technique which could provide global planarization for silicon.The CP-CMP technology maintains the advantages of single abrasive slurry,improving its defects such as low removal rate,edge collapse and so on.Based on the existing research results of composite abrasives slurry,aiming to enhance material removal rate and surface quality and improve slurry stability,the preparation and optimization for this kind of slurry were studied in this paper,and the adsorption of the two kind abrasives was enhanced.At last,the composite abrasives slurry with high performance was made.The details of the research can be summarized as follows:Firstly,the adsorption characteristics of cationic polyelectrolyte PDADMAC and anionic polyelectrolyte PSS on BGF particles are investigated.The charging characteristics of BGF particles are changed using electrostatic self-assembly technology.Two kinds of n-SiO2/BGF and PEi-SiO2/BGF composite abrasives are obtained.The as-prepared samples are analyzed by TEM.Secondly,the copper CMP experiments were carried out with the composite abrasives slurry prepared above.The polishing performance with single abrasives slurry,unmodified BGF+SiO2 compound abrasives slurry and cation-modified BGF+SiO2 composite abrasives slurry was studied.The polishing mechanism of adsorption layers of polyelectrolyte and free SiO2 abrasives in slurry were analyzed.Lastly,the comparative analysis of two kinds of composite abrasive slurry of silicon polishing performance.Quality of the polished silicon surface and stability of the slurry were evaluated at last.The study of this paper provides a systemic researching method for enhancing the material removal rate and polishing quality,and improving the slurry performance.It has reference meanings for composite abrasives slurry to further exert its advantages in CMP technology.