Appeal No. 2005-1011 Page 6
Application No. 09/921,588
removal of the surface material of the object by adjusting the concentrations of the
polishing solution at respective of the nozzles. The concentration of the polishing
solution can be lowered in an area where the removal rate is high while the
concentration of the polishing solution can be raised in an area where the removal rate
is low. By providing an optimum distribution of concentrations of the polishing solution
along a radial direction, Kimura teaches it is possible to improve the flatness of the
wafer significantly.
According to a second embodiment of Kimura (see Figures 3-4) there is provided
a polishing apparatus for polishing a surface of an object and including a turntable
having a polishing cloth mounted on an upper surface thereof, a top ring for holding and
pressing the object against the polishing cloth, at least one solution nozzle for supplying
a polishing solution, containing abrasive material, having a common concentration, and
a plurality of diluting liquid supply nozzles arranged in a radial direction for supplying
adjustable volumes of diluting liquid so as to form a distribution of polishing solution of
different concentrations by diluting the polishing solution with the diluting liquid on the
polishing cloth. Each of the water supply nozzles is provided with a needle valve so that
the volume of water supplied therefrom can be adjusted. By adjusting the volume of
water delivered in the radial direction through each of the water supply nozzles, it is
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