INFLUENCE OF ADHESION OF SILICA AND CERIA ABRASIVE NANOPARTICLES ON CHEMICAL-MECHANICAL PLANARISATION OF SILICA SURFACES

The direct measurement of adhesion between abrasive nanoparticles of irregular shape, used in the semiconductor industry in the process of chemical-mechanical planarisation (CMP), and a silica surface is reported. The adhesion of ceria and silica nanoparticles to the silica surface was measured in multiple chemistries of different CMP slurries using a specially developed AFM method. Using this method, the influence of adhesion on the main parameters of CMP, removal rate, defectivity and scratches was studied. A direct correlation between adhesion and removal rate was observed. Comparing the measured defectivity and adhesion, the presence of some correlation between these parameters was observed. Both adhesion and the shape of the abrasive particles influenced defectivity and micro-scratches. Direct measurements of the adhesion between abrasive nano-particles and surface can be used in the screening of new slurries and various modelling related to the wear of the surfaces.