Polishing composition and method of polishing a substrate having enhanced defect reduction
View Patent ↗An aqueous alkaline chemical mechanical polishing composition includes a quaternary ammonium compound having a phenyl group which enables enhanced reduction of defects on silicon oxide substrates and enables good silicon oxide removal rates during chemical mechanical polishing.
1. A chemical mechanical polishing composition consisting of water; 10 to 20 wt % colloidal silica having a average particle size of 100 to 150 nm; optionally a pH adjusting agent; optionally a biocide; a pH of 10-12; and 0.1 to 0.5 wt % quaternary ammonium compound having formula (I):
wherein R 1 , R 2 and R 3 are independently selected from the group consisting of phenyl, benzyl, and linear or branched C 1 -C 5 alkyl; and X − is an anion selected from the group consisting of Br − , Cl − , I − , F − and OH − .
2. The chemical mechanical polishing composition of claim 1 , wherein the pH adjusting agent is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium salt and mixtures thereof.
3. The chemical mechanical polishing composition of claim 1 , wherein the quaternary ammonium compound has the formula (I):
wherein R 1 , R 2 and R 3 are independently selected from the group consisting of C 1 -C 2 alkyl and X − is an anion selected from the group consisting of Br − , Cl − and OH − .
4. The chemical mechanical polishing composition of claim 1 , wherein the quaternary ammonium compound of formula (I) is selected from the group consisting of phenyltrimethylammonium chloride, phenyltrimethylammonium bromide, phenyltrimethylammonium hydroxide and mixtures thereof.