Fitzpatrick, Cella, Harper & Scinto
Chemical mechanical polishing apparatus and method
 A chemical mechanical polishing apparatus and method can polish a surface of an object very precisely at a high speed irrespective of the presence of a local defect on the surface to be polished. By using a multiplex ring-shaped polishing pad, an effective surface to be polished is increased, and very precise and uniform polishing can be performed at a high speed. By using a plurality of polishing pads, having different diameters smaller than the diameter of the surface to be polished, provided with an interval on the same revolution radius on a revolution table, or by using a plurality of polishing pads, having the same diameter smaller than the diameter of the surface to be polished, provided at positions having different revolution radii on a revolution table, very precise and uniform polishing can be performed. 
Canon Kabushiki Kaisha
B B B B
B24B B24B B24B B24B
inventional inventional inventional inventional
Kyoichi Kazuo Matsuomi Shinzo
Miyazaki Takahashi Nishimura Uchiyama