Method and apparatus for uniform electroplating of integrated circuits using a variable field shaping element
OwnerSteven T. Mayer, Richard Hill +5inventors
InventorsSteven T. Mayer, Richard Hill, Alain Harrus, Evan Patton, Robert Contolini, Steve Taatjes, Jon Reid
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Abstract
An electrochemical reactor is used to electrofill damascene architecture for integrated circuits. A shield is used to screen the applied field during electroplating operations to compensate for potential drop along the radius of a wafer. The shield establishes an inverse potential drop in the electrolytic fluid to overcome the resistance of a thin film seed layer of copper on the wafer.
Claims25
An electrochemical reactor having a variable field-shaping capability for use in electroplating thin films, comprising:
- a reservoir operably configured to retain an electrolytic fluid;
- a cathode and an anode disposed in said reservoir to provide an electrical pathway through electrolytic fluid when said electrolytic fluid is present in said reservoir;
- at least one of said cathode and said anode including a wafer-holder;
- a shield positioned in said electrical pathway between said cathode and said anode and operably configured for shielding a surface area on a wafer in said wafer-holder when said wafer is held in said wafer-holder during electroplating operations,
- said shield including means, operable during electroplating operations, for selectively varying a parameter selected from the group consisting of
- a quantity of shielded surface area,
- a distance separating said shield from a wafer in said wafer holder, and
- combinations thereof.
A method of electroplating films for use in integrated circuits through an electrochemical reactor having a variable field-shaping capability, said method comprising the steps of:
- placing a wafer in electrical contact with one of a cathode and an anode in an electrochemical reactor;
- conducting electricity through an electrolytic fluid between said cathode and said anode for electroplating a film onto said wafer;
- and
- actuating a shield to vary an electric field around said wafer holder during electroplating operations,
- wherein said step of actuating a shield includes actuating said shield during electroplating operations to vary a parameter selected from the group consisting of
- a quantity of shielded surface area,
- a distance separating said means for selectively masking a surface area from a wafer in said wafer holder, and
- combinations thereof.
Dependencies are inferred from the claim text.