PURPOSE: To measure flatness during the actual polishing work of a polishing surface plate, and to improve the dimensional accuracy of a semiconductor wafer by providing a monitor means monitoring the surface state of the polishing surface of the polishing surface plate during the polishing work in a noncontact manner.
CONSTITUTION: A sensor 7 for measuring flatness is arranged in the radial direction of a surface plate 1 just above the polishing surface 2 of a polishing surface plate 1. The sensor 7 is connected to a flatness monitor device 8, and both the sensor 7 and the flatness monitor device 8 constitute a monitor means. A controller 9 conducts required arithmetic processing on the basis of the result of the measurement of flatness with time from the sensor 7 and the device 8, and secularly sets the optimum conditions of polishing of the polishing surface 2. Accordingly, dimensional accuracy including the flatness of the surface to be polished of a wafer is improved.
NAKABAYASHI SHINICHI
ICHIKAWA NAKABA
MURAMATSU TAKASHI
