Increased wetting of colloidal silica as a polishing slurry

A method of polishing a sapphire surface, comprising:

• abrading a sapphire surface with a rotating polishing pad and a polishing composition,
• wherein the polishing composition comprises an effective amount of colloidal silica and a surfactant, the colloidal silica has a particle size distribution of from about 5 nm to about 120 nm;
• the ratio of the standard deviation of the particle size of the colloidal silica (CT) to the mean particle size of the colloidal silica (r) is from about 0.30 to about 0.90;
• and the surfactant is one represented by the following formula I or II,
• wherein R10 is a C3-C20 alkyl or alkenyl group, R11 is a C4-C20 alkyl, n, m, and k are independently integers of 1 to 20, and
• wherein the surfactant has a concentration of between about 1,000 ppm and about 2,000 ppm in the polishing composition.