Abstract

Polishing laps and apparatus incorporating such polishing laps for polishing workpieces such as semiconductor wafers are disclosed. The polishing laps are made from a cured mixture of an epoxy resin and a filler material, and preferably have at least a portion that is transparent to light. The polishing lap is preferably mounted on rigid polishing wheel or the like with or without an intervening layer such as an elastic layer. Polishing apparatus incorporating the polishing lap preferably include a light source for directing a beam of light toward the transparent portion of the polishing lap to enable the light beam to reflect from the working surface of the workpiece as the workpiece is being polished by the polishing lap. The apparatus also preferably includes a light detector for detecting light reflected from the surface of the workpiece. Such light can provide information, as on the status of the working surface as polishing progresses and can provide an indication of when polishing has reached a desired end point.