Method for planarizing semiconductor wafers with a non-circular polishing pad

A process for planarizing semiconductor wafers comprising the steps of:

• rotating a platen about a center axis, the platen having a non-circular pad mounted thereon, the non-circular pad having a non-circular peripheral edge;
• holding a surface of a semiconductor wafer in juxtaposition relative to the non-circular pad;
• rotating the wafer about a wafer center and moving the wafer across the non-circular pad;
• and
• maintaining the wafer center within a circumscribed boundary around the non-circular pad, the boundary being defined by a circle about the center axis and tangential to an outermost portion of the non-circular peripheral edge of the non-circular pad.

A process for planarizing semiconductor wafers comprising the steps of:

• rotating a platen at a preselected velocity about a center axis, the platen having a non-circular pad mounted thereon, the non-circular pad having a non-circular peripheral edge;
• rotating a semiconductor wafer about a wafer center in the same direction that the platen is rotating;
• holding a surface of the semiconductor wafer in juxtaposition relative to the non-circular pad to polish the surface of the semiconductor wafer;
• moving the wafer across the non-circular pad;
• and
• moving at least a portion of the wafer to a location beyond the peripheral edge of the non-circular pad to facilitate a uniform polish of the surface of the semiconductor wafer.