Abrading – Abrading process – Glass or stone abrading
Reexamination Certificate
2002-08-14
2004-04-13
Hail, III, Joseph J. (Department: 3723)
Abrading
Abrading process
Glass or stone abrading
C451S028000, C451S262000, C451S288000
Reexamination Certificate
active
06719615
ABSTRACT:
BACKGROUND OF INVENTION
Chemical mechanical polishing (CMP) is generally known in the art. For example U.S. Pat. No. 5,177,908 issued to Tuttle in 1993 describes a finishing element for semiconductor wafers, having a face shaped to provide a constant, or nearly constant, surface contact rate to a workpiece such as a semiconductor wafer in order to effect improved planarity of the workpiece. U.S. Pat. No. 5,234,867 to Schultz et al. issued in 1993 describes an apparatus for planarizing semiconductor wafers which in a preferred form includes a rotatable platen for polishing a surface of the semiconductor wafer and a motor for rotating the platen and a noncircular pad is mounted atop the platen to engage and polish the surface of the semiconductor wafer. Fixed abrasive finishing elements are known for polishing. Illustrative examples include U.S. Pat. No. 4,966,245 to Callinan, U.S. Pat. No. 5,823,855 to Robinson, and WO 98/06541 to Rutherford.
An objective of polishing of semiconductor layers is to make the semiconductor layers as nearly perfect as possible.
BRIEF SUMMARY OF INVENTION
Current finishing elements and equipment can suffer from being costly to manufacture. Generally very complex mechanical equipment used when finishing semiconductor wafers. Complex, expensive, and bulky mechanical drives are generally used for generating polishing pad and wafer polishing motions. Also current finishing elements for semiconductor wafers generally have coextensive surface layers which can limit their versatility in some demanding finishing applications. Current polishing pads are generally larger than the workpiece being finished which consumes precious floor space in a semiconductor fab. Still further, current finishing apparatus are not capable of supplying a parallel finishing motion to finishing elements solely through magnetic coupling forces. Still further, current finishing apparatus are not capable of supplying multiple different parallel finishing motions to multiple finishing elements solely through magnetic coupling forces. Still further, current finishing apparatus are not capable of supplying multiple different parallel finishing motions to multiple different finishing elements solely through magnetic coupling forces. Still further, current finishing apparatus are not capable of supplying refining motion(s) to refining element(s) solely through magnetic coupling forces wherein the refining element(s) inside an enclosed refining chamber and the driving element is external to the enclosed refining chamber. Still further, current finishing apparatus are not capable of supplying a parallel finishing motion to refining elements solely through magnetic coupling forces while electrodeposition and/or electropolishing. Still further, a lack of the above characteristics in a finishing element reduces the versatility of the refining method(s) which can be employed for semiconductor wafer surface refining. Still further, current finishing pads can be limited in the way they apply pressure to the abrasives and in turn against the semiconductor wafer surface being finished. These unwanted effects are particularly important and can be deleterious to yield and cost of manufacture when manufacturing electronic wafers which require extremely close tolerances in required planarity and feature sizes.
It is an advantage of this invention to improve the finishing method for semiconductor wafer surfaces to make them as perfect as possible. It is an advantage of this invention to make refining elements and refining equipment with a lower cost of manufacture and reduce the mechanical complexity of the refining equipment and thus also reduce the cost of refining a semiconductor wafer surface or workpiece surface. It is a preferred advantage of this invention to develop refining apparatus and refining elements that can be smaller than the workpiece being refined. It is further an advantage of the invention to develop refining apparatus that are capable of supplying a parallel refining motion to refining elements solely through magnetic coupling forces. It is further a preferred advantage of the invention to develop current finishing apparatus that are capable of supplying multiple different parallel refining motions to multiple different refining elements solely through magnetic coupling forces. It is further a preferred advantage of the invention to develop current finishing apparatus that are capable of supplying a plurality of independent parallel refining motions to multiple different refining elements solely through magnetic coupling forces. It is further an advantage of the invention to develop current refining apparatus that are capable of supplying multiple different parallel refining motions to multiple different, independently controlled refining elements solely through magnetic coupling forces. It is further an advantage of the invention to develop current refining apparatus that are capable of supplying multiple different refining energies, actions, and/or parallel motions to multiple different, independently controlled refining elements. It is further a preferred advantage of the invention to develop current refining apparatus, refining elements, and refining capability that can add and remove material from the workpiece surface being refined. It is further a preferred advantage of the invention to develop current refining apparatus, refining elements, and refining capability that can add and remove material from the workpiece surface being refined using similar and/or identical drive elements. It is an advantage of the invention to develop a refining element which has a unique way of applying pressure to the unitary and/or a plurality of discrete refining surface(s) and to the workpiece surface being refined. It is an advantage of the invention to develop a refining element which has a unique way of applying refining energy or energies to the unitary and/or a plurality of discrete refining surface(s) and to the workpiece surface being finished. It is further an advantage of this invention to help improve yield and lower the cost of manufacture for finishing of workpieces having extremely close tolerances such as semiconductor wafers. It is further an advantage of this invention to help improve versatility and control which will in turn improve yield, reduce consumable costs, and lower the cost of manufacture for refining of workpieces having extremely close tolerances such as semiconductor wafers. Preferred embodiments accomplish one or more of the above advantages with a new structure and function in a new way to give the new and useful result.
A preferred embodiment of this invention is directed to a method for refining a semiconductor wafer surface comprising a step of providing a magnetically responsive refining element having a refining surface free of any physically connected mechanical movement mechanism; a step of providing a magnetic driving element having a driving mechanism; a step of positioning the semiconductor wafer being refined with a holder proximate to the magnetically responsive refining element and between the magnetically responsive refining element and magnetic driving element; and a step of applying an operative refining motion comprising a magnetically induced parallel operative refining motion in the interface between the semiconductor wafer surface being refined and the refining surface of the magnetically responsive refining element for changing the amount of material on the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method for refining a semiconductor wafer surface comprising a step of providing a magnetically responsive refining element having a first electrode; a step of providing a magnetic driving element operatively connected to a driving mechanism; a step of providing a semiconductor wafer surface having an operative electrical contact forming a second operative electrode between the magnetically responsive refining element and the magnetic driving element; a step of magnetically coupling the magnetically
Beaver Creek Concepts Inc
Hail III Joseph J.
Thomas David B.
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