Method and apparatus for improving planarity of chemical-mechanical planarization operations
First Claim
1. A chemical mechanical planarization apparatus comprisinga platen having a horizontal, planar upper surface;
- a slurry-wetted, uniformly-thick polishing pad affixed to said upper surface;
a wafer carrier having a lower planar surface to which one side of a semiconductor wafer is removably attachable, the other side of said wafer being disposed against said slurry-wetted polishing pad; and
means for imparting non-rotational motion to said platen upper surface, said motion being parallel to that upper surface, and also providing every point on that upper surface with identical during same time interval.
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Abstract
A method and apparatus for improving planarity of chemical mechanical planarization of semiconductor wafers. The wafer is affixed to the planar surface of a wafer carrier. A planar platen, on which is mounted a polishing pad, is moved about in a plane parallel to the pad surface with either an orbital, fixed-direction vibratory, or random-direction vibratory motion. In one embodiment of the invention, pressure between the surface of the wafer to be polished and the moving polishing pad is generated by the force of gravity acting on at least the wafer and the carrier; in another it is provided by a mechanical force applied normal to the wafer surface. The polishing pad is wetted with a slurry having abrasive particles suspended in a liquid which may be chemically reactive with respect to at least one material on the wafer.
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Citations
25 Claims
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1. A chemical mechanical planarization apparatus comprising
a platen having a horizontal, planar upper surface; -
a slurry-wetted, uniformly-thick polishing pad affixed to said upper surface; a wafer carrier having a lower planar surface to which one side of a semiconductor wafer is removably attachable, the other side of said wafer being disposed against said slurry-wetted polishing pad; and means for imparting non-rotational motion to said platen upper surface, said motion being parallel to that upper surface, and also providing every point on that upper surface with identical during same time interval. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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- 17. A method for performing a chemical-mechanical planarization operation on a wafer having front-side and back-side planar surfaces, said method comprising the step of disposing the front-side surface against an abrasive planar surface, said abrasive planar surface being moved non-rotationally, and in a man every point on said front-side surface experiences both virtually identical pressure against said abrasive planar and identical relative motion, with respect to said abrasive planar surface, during the same time interval.
Specification