Method and apparatus for chemical polishing using field responsive materials
AssigneeAdvanced Micro Devices, Inc.
InventorEric N. Paton
Life of this patent
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Abstract
A process for, and apparatus for, Chemically-Mechanically Polishing (CMP) a semiconductor wafer with a slurry including ElectroRheological (ER) and/or MagnetoRheological (MR) fluids. The combination of the materials and an electric field provides inherent tuning of polishing rates, locally and globally, and improves flatness and uniformity, as well as minimizing recession and erosion.
Claims20
An integrated circuit manufacturing process for Chemically Mechanically Polishing (CMP) a metal layer on a semiconductor wafer, said wafer having a front side, said process comprising the steps of:
- providing a polishing apparatus including a platen having a polishing pad thereon;
- flowing a slurry including a fluid including a field responsive material exhibiting a characteristic dramatic rheological change in its viscosity in response to an external electromagnetic field on said polishing pad;
- establishing an electromagnetic field across a portion of said fluid, said field being of sufficient intensity to control the viscosity of said fluid contacting said metal layer to induce abrasion of said metal layer on said front surface of said wafer;
- and
- moving said wafer across said polishing pad.
In an integrated circuit manufacturing process for Chemically Mechanically Polishing a metal layer on a semiconductor wafer, said method including causing relative motion between said wafer and a polishing pad and flowing a polishing slurry between said wafer and said polishing pad, the improvement comprising:
- flowing said polishing slurry including flowing an insulating ElectroRheological (ER) fluid;
- and
- establishing an electric field across said ER fluid, said electric field having an intensity sufficiently high to cause said ER fluid to stiffen enough to sustain abrasion of said metal layer.
An integrated circuit manufacturing process for Chemically Mechanically Polishing (CMP) a metal layer on a semiconductor wafer, said wafer having a front side, an edge surface, and a back side, said process comprising the steps of:
- providing a polishing apparatus including a platen having a polishing pad thereon;
- flowing an insulating ElectroRheological (ER) fluid comprising a continuous phase fluid including ER particles dispersed therein on said polishing pad;
- establishing an electric field within said ER fluid;
- and rotating said wafer across said polishing pad.
An integrated circuit manufacturing process for Chemically Mechanically Polishing (CMP) a metal layer on a semiconductor wafer, said wafer having a front side, an edge surface, and a back side, said process comprising the steps of:
- providing a polishing apparatus including a platen having a polishing pad thereon;
- flowing an insulating MagnetoRheological (MR) fluid comprising a continuous phase fluid including MR particles dispersed therein on said polishing pad;
- establishing a global magnetic field about said wafer, said global magnetic field being configured to adjust the relative polish rates of said CMP across said wafer to reduce WIWNU;
- and
- rotating said wafer across said polishing pad.
Dependencies are inferred from the claim text.