AMMONIUM-SALT-ADDED SILICA SLURRY FOR THE CHEMICAL-MECHANICAL POLISHING OF THE INTERLAYER DIELECTRIC FILM PLANARIZATION IN ULSIS

Based on the theory of colloid, a new KOH-free silica slurry is develo ped for chemical mechanical polishing (CMP) to planarize the interlaye r dielectric films in ULSI's. The ammonium salt addition to the slurri es of pH = 6-7 promotes the silica particle agglomeration in the slurr y, and enlarges the effective abrasive particle size. The particle agg lomeration yields a high polishing rate due to increasing of the mecha nical effect, and good particle removability with scrub cleaning is ac hieved. The ammonium salt-added slurry provides the high-speed CMP wit hout alkaline-metal contamination to the LSI fabrication line.