A polishing apparatus is described. The polishing apparatus includes a
rotatable platen, a drive mechanism to incrementally advance a polishing
sheet having a polishing surface in a linear direction across the platen,
a subpad on the platen to support the polishing sheet, the subpad having
a groove formed therein, and a vacuum source connected to the groove of
the subpad and configured to apply a vacuum sufficient to pull portions
of the polishing sheet into the groove of the subpad to induce a groove
in the polishing surface.