Polishing pad and surface polishing method

Abstract

A workpiece is pinched from above and below by polishing pads attached to the inner surfaces of a pair of upper and lower rotary platens. A slurry is dropped between the workpiece and the polishing pads to polish the workpiece. The polishing pad is comprised of a base layer, and a sheet-shaped nap layer, which is laminated on the base layer and is made of a soft plastic foam. The nap layer is formed of closed pores, whose surface is covered with non-foaming skin layers and which involves pores (air bubble) in the nap layer without opening the pores in the surface. The polishing pad is used in combination with a colloidal slurry whose abrasive grains are colloidal silica in order to polish a surface of the workpiece.

Dependencies are inferred from the claim text.