Method of fabricating a copper damascene structure
AssigneeFerro Corporation
InventorsYuzhuo Li, Jason Keleher
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Abstract
The present invention provides a method of removing copper overlaying a tantalum-based barrier layer during the fabrication of a copper damascene structure having a plurality of copper lines. The method includes providing a chemical-mechanical polishing slurry and polishing the copper layer using the slurry until the tantalum-based barrier layer is exposed. The slurry includes an oxidizing agent that releases free radicals and a non-chelating free radical quencher that retards the corrosion of said copper lines during chemical mechanical polishing. Preferred non-chelating free radical quenchers are ascorbic acid, thiamine, 2-propanol, and alkyl glycols. The present invention also provides copper damascene structures formed according to the method.
Claims19
A method of removing copper overlaying a tantalum-based barrier layer during the fabrication of a copper damascene structure having a plurality of copper lines, said method comprising:
- providing a chemical-mechanical polishing slurry comprising:
- an oxidizing agent that releases free radicals;
- and
- a non-chelating free radical quencher that retards the corrosion of said copper lines during chemical mechanical polishing selected from the group consisting of thiamine, 2-propanol, alkyl glycols, and combinations of the foregoing;
- and
- polishing said copper layer using said slurry until said tantalum-based barrier layer is exposed.
A method of removing copper overlaying a tantalum-based barrier layer during the fabrication of a copper damascene structure having a plurality of copper lines, said method comprising:
- providing a chemical-mechanical polishing slurry comprising:
- hydrogen peroxide;
- and
- a non-chelating free radical quencher that retards the corrosion of said copper lines during chemical mechanical polishing selected from the group consisting of ascorbic acid, thiamine, 2-propanol, alkyl glycols, and combinations of the foregoing;
- and
- polishing said copper layer using said slurry until said tantalum-based barrier layer is exposed.
A method of removing copper overlaying a tantalum-based barrier layer during the fabrication of a copper damascene structure having a plurality of copper lines, said method comprising:
- providing a chemical-mechanical polishing slurry comprising:
- from about 3% to about 10% by weight of abrasive particles;
- from about 0.5% to about 5.0% by weight of hydrogen peroxide;
- and
- from about 0.1% to about 1% by weight of ascorbic acid;
- and
- polishing said copper layer using said slurry until said tantalum-based barrier layer is exposed.
Dependencies are inferred from the claim text.