Method for forming a conductive copper structure
First Claim
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1. A method of forming a metal layer over a semiconductor wafer, comprising:
- exposing a copper oxide on a copper seed layer located over a semiconductor substrate to a substantially copper-free reducing agent solution, such that said copper oxide is substantially converted to elemental copper, wherein said substantially copper-free reducing agent solution comprises a reducing agent selected from the group consisting of formate, formaldehyde, dimethylamine borane, ammonium hypophosphite, and hydrazine sulfate; and
electrochemically depositing a second copper layer over said copper seed layer.
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Abstract
The present invention provides, in one embodiment, a method of forming a metal layer over a semiconductor wafer. The method includes the chemical reduction of copper oxide (105) over the deposited copper seed layer (110) by exposure to a substantially copper-free reducing agent solution (120), such that the copper oxide (105) is substantially converted to elemental copper, followed by electrochemical deposition of a second copper layer (125) over the copper seed layer (110). Such methods and resulting conductive structures thereof may be advantageously used in methods to make integrated circuits comprising interconnection metal lines.
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18 Claims
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1. A method of forming a metal layer over a semiconductor wafer, comprising:
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exposing a copper oxide on a copper seed layer located over a semiconductor substrate to a substantially copper-free reducing agent solution, such that said copper oxide is substantially converted to elemental copper, wherein said substantially copper-free reducing agent solution comprises a reducing agent selected from the group consisting of formate, formaldehyde, dimethylamine borane, ammonium hypophosphite, and hydrazine sulfate; and
electrochemically depositing a second copper layer over said copper seed layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of making an integrated circuit comprising:
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forming active devices over or in a semiconductor substrate;
forming interconnect metals lines on a dielectric layer located over said active devices including;
exposing a copper oxide on a copper seed layer located over said semiconductor substrate to a substantially copper-free reducing agent solution, such that said copper oxide is substantially converted to elemental copper, wherein said substantially copper-free reducing agent solution comprises a reducing agent selected from the group consisting of formate, formaldehyde, dimethylamine borane, ammonium hypophosphite, and hydrazine sulfate;
depositing, using an electrochemical deposition tool, a second copper layer over said seed layer;
connecting said interconnects with said active devices to form an operative integrated circuit. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification