摘要:
The treatment of solutions of metal ions with redox polymers under conditions to reduce the ions to a lower valence. The resulting solutions of the lower valence ions are separated from the polymers, and the polymers are regenerated for further use in such treatment. The method of the invention is employed to convert high valence, toxic metal ions to lower valence ions of reduced toxicity. Preferably, the electronically conductive polymer is mounted on a suitable support, and a solution of the toxic metal ion is brought into contact with the polymer. A variety of redox polymers, in particular, electronically conductive polymers, may be used in the practice of the invention, and individual such polymers may be structurally altered to suit particular metal ions. Polymers especially contemplated for use in the invention are polypyrroles, polyanilines and polythiophenes. All of these polymers are characterized as redox polymers with a positive charge on their backbones. In general, suitable polymers are redox polymers bearing a positive charge on their backbones with an E.sub.o of the (surface) redox couple sufficiently negative to react with a metal ion of interest. Thus, for example, an E.sub.o more negative than 1.16V is preferred for the recovery of Cr(VI).
摘要:
A method of conditioning pads used in the polishing of semiconductor wafers containing copper circuitry. The method includes applying a treatment solution that contains a reactant for particulate copper-containing debris on the pad resulting from the copper circuitry. Preferably, the reactant is a carboxylic acid present in a concentration of from about 0.1 to about 10 weight percent in a solution. The pH of the solution may be adjusted to the range from about 1 to about 6 with a compatible base.
摘要:
A method for polishing a metal layer on a workpiece is provided wherein relative motion is produced between the metal layer and a polishing surface and wherein the metal layer has a polish resistant film thereon. The metal layer is first pre-treated to substantially remove the polish resistant film. Next, the metal layer is polished at low pressure between the metal layer and the polishing surface in the presence of a polishing solution. The pretreating may be accomplished by, for example, sputtering, polishing the polish-resistant film in the presence of abrasive polishing solution, polishing the polish-resistant film at higher pressures between the film and the polishing surface, maintaining the temperature of the pretreating step to be substantially between 10 degrees Centigrade and 30 degrees Centigrade, and chemically removing the film.
摘要:
A method of improving planarity of semiconductor wafer surfaces containing damascene and dual-damascene circuitry using chemical-mechanical polishing techniques. The method includes using a first polishing step to substantially remove excess surface metal up to a detected end point. After rinsing, a second step of chemical-mechanical polishing is applied, using a second slurry that has a higher selectivity for dielectric than metal, preferably from 1.8 to 4 or more times greater. The second step of polishing, in accordance with the invention, has been found to substantially eliminate dishing and improve planarity.