Wafer edge deplater for chemical mechanical polishing of substrates
AssigneeInternational Business Machines Corporation
InventorCyprian Emeka Uzoh
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Abstract
A device for electrochemically deplating metal from side edges and a backside of a semiconductor wafer or substrate. The device includes a shaped cathode having a shape substantially corresponding to a shape of at least a portion of the semiconductor wafer, such that the shaped cathode at least partially covers the backside and at least partially covers the side edges of the semiconductor wafer. The position of at least one of the semiconductor wafer and the shaped cathode is altered by position altering apparatus during the electrochemical deplating.
Claims28
A device for electrochemically deplating metal from side edges and a backside of a semiconductor wafer, comprising:
- a shaped cathode having a shape substantially corresponding to a shape of at least a portion of the semiconductor wafer, such that the shaped cathode surrounds at least a portion of the backside and at least a portion of the side edge of the semiconductor wafer;
- and
- means for altering a position of at least one of the semiconductor wafer and the shaped cathode during the electrochemical deplating.
A method for electrochemically deplating metal from side edges and a backside of a semiconductor wafer, the method comprising the steps of:
- placing a shaped cathode having a shape substantially corresponding to a shape of at least a portion of the semiconductor wafer, such that the shaped cathode surrounds at least a portion of the backside and side edges of the semiconductor wafer in the vicinity of at least a portion of the backside and side edges of the semiconductor wafer;
- placing an anode in contact with at least a portion of a front side of the semiconductor wafer;
- altering a position of at least one of the semiconductor wafer and the shaped cathode;
- directing an electrolyte between the semiconductor wafer and the shaped cathode;
- and
- supplying current to the anode and the cathode for a time sufficient to substantially completely deplate metal deposited on the side edges and backside of the semiconductor wafer.
A system for deplating undesired metal from a substrate, the system comprising:
- a shaped cathode having an upper surface having a contour corresponding to at least a portion of the substrate;
- means for altering a position of at least one of the semiconductor wafer and the shaped cathode;
- at least one source of at least one material for removing the metal and directing the material between the shaped cathode and the substrate;
- and
- a power source for supplying power to the shaped cathode.
Dependencies are inferred from the claim text.