The present invention relates to a polishing composition for a
semiconductor wafer which is excellent in polishing property, and a
polishing method. The polishing composition for a semiconductor wafer
comprises colloidal silica consisting of non-spherical silica particles
having a ratio of long axis to short axis of 1.5 to 15. The polishing
method for a semiconductor wafer uses the polishing composition. The
polishing composition can provide a remarkably high polishing rate
compared with a polishing composition using spherical colloidal silica,
and can provide good mirror-polishing without causing scratches. In
addition, small alkali metal content enables reduction of adverse effects
on a semiconductor wafer, such as residual abrasives after polishing.