System and method for polishing and planarizing semiconductor wafers using reduced surface area polishing pads and variable partial pad-wafer overlapping techniques
AssigneeLam Research Corporation
InventorsJohn M. Boyd, Yehiel Gotkis, Rod Kistler
Life of this patent
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Abstract
A system and method for polishing semiconductor wafers includes a variable partial pad-wafer overlap polisher having a reduced surface area, fixed-abrasive polishing pad and a polisher having a non-abrasive polishing pad for use with an abrasive slurry. The method includes first polishing a wafer with the variable partial pad-wafer overlap polisher and the fixed-abrasive polishing pad and then polishing the wafer in a dispersed-abrasive process until a desired wafer thickness is achieved.
Claims17
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.
Dependencies are inferred from the claim text.