System and method for polishing and planarizing semiconductor wafers using reduced surface area polishing pads and variable partial pad-wafer overlapping techniques

A method of providing controlled regional polishing of a semiconductor wafer comprising;

• loading a semiconductor wafer on a wafer receiving surface of a rotatable wafer carrier and rotating the semiconductor wafer;
• and
• moving a polishing pad mounted on a rotating polishing pad carrier against the rotating semiconductor wafer to a partially overlapping position, wherein the polishing pad comprises a polishing pad material positioned along a circumference of the polishing pad and extending radially inwardly a portion of a radius of the polishing pad, and wherein the polishing pad material defines a central region lacking polishing pad material and symmetric about a diameter of the polishing pad;
• and
• maintaining a first pressure between the partially overlapping semiconductor wafer and polishing pad.

A method of planarizing and polishing semiconductor wafers comprising:

• rotating a first polishing pad about a central axis, wherein the polishing pad has a polishing pad material positioned along a circumference of the first polishing pad and extending radially inwardly a portion of a radius of the first polishing pad, and wherein the polishing pad material defines a central region lacking polishing pad material and symmetric about a diameter of the first polishing pad;
• pressing a portion of the polishing pad material on the first polishing pad against a portion of a rotating semiconductor wafer, wherein the first polishing pad partially overlaps the semiconductor wafer;
• and
• maintaining a first pressure between the first polishing pad and the semiconductor wafer.

A semiconductor wafer polishing system comprising:

• a first wafer polisher comprising:
• a rotatable wafer carrier having a wafer receiving surface for releasably retaining a semiconductor wafer;
• a rotatable polishing pad comprising a fixed-abrasive polishing pad material positioned along a circumference of the polishing pad and extending radially inwardly a portion of a radius of the polishing pad, wherein the fixed-abrasive polishing pad material defines a central region lacking polishing pad material and symmetric about a diameter of the polishing pad;
• a rotatable polishing pad carrier oriented substantially parallel to the wafer receiving surface and configured to movably position the polishing pad in a partially overlapping position with respect to the semiconductor wafer, wherein the polishing pad contacts and rotates against a portion of a surface of the semiconductor wafer;
• and
• a rotatable pad dressing assembly having a surface positioned substantially coplanar with the surface of the semiconductor wafer on the wafer carrier, wherein the rotatable pad dressing assembly rotates and contacts a first portion of the polishing pad;
• a dispersed-abrasive process station, the dispersed-abrasive process station comprising:
• a second rotatable wafer carrier having a wafer receiving surface for releasably retaining the semiconductor wafer;
• and
• a second polishing pad mounted on a polishing pad transport, the polishing pad transport configured to move the polishing pad against the semiconductor wafer, the second polishing pad comprising a non-abrasive polishing pad material positioned to receive a polishing slurry and transport the polishing slurry against a surface of the semiconductor wafer;
• and
• a semiconductor wafer transfer mechanism movable between the first wafer polisher and the dispersed-abrasive station, wherein a first portion of a wafer polishing process for the wafer is applied at the first wafer polisher and a second portion of the wafer polishing process is applied at the dispersed-abrasive polishing station.