Appeal No. 2005-1011 Page 9
Application No. 09/921,588
26 to retain wafer 12 and a housing 28 to retain pad 16. Carrier 26 is used to rotate
wafer 12 against pad 16 which is directed upward against the wafer during polishing.
Housing 28 serves somewhat the same purpose as carrier 26 in that it retains pad 16.
Pad 16 and housing 28 form a chamber which can receive air pressure 40 through an
inlet port 42. Placed between pad 16 and chamber 44 is manifold 22 having a plurality
of apertures 24.
The air pressure and/or fluid extending through inlet port 42 causes manifold 22
and pad 16 to extend upward. In so doing, manifold 22 may flex in an arcuate pattern as
shown. Uneven pressure may result in a relatively severe, circular polishing pattern
near the center of wafer 12. The circular polishing pattern at or near the center is
dictated by the length of oscillation vectors 20. Abrasion primarily at the center region
will not produce a desired uniformity across the entire wafer surface. Alternatively,
polish only at the center may not remove thicker films which may not exist at the
perimeter of the wafer, due to uneven chemical vapor deposition (CVD) or sputter
deposition techniques.
To offset the uneven nature by which pad 16 might abrade wafer 12 surface,
uneven delivery of slurry may be desired. The uneven fluid delivery is shown as
reference numeral 48, where the length of arrows indicate a greater channeling of fluid
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