Wafer flood polishing
AssigneeInternational Business Machines Corporation
InventorsWilliam J. Cote, Michael A. Leach
Life of this patent
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Abstract
In a chem-mech polishing process for planarizing insulators such as silicon oxide and silicon nitride, a pool of slurry is utilized at a temperature between 85.degree. F.-95.degree. F. The slurry particulates (e.g. silica) have a hardness commensurate to the hardness of the insulator to be polished. Under these conditions, wafers can be polished at a high degree of uniformity more economically (by increasing pad lifetime), without introducing areas of locally incomplete polishing.
Claims20
In a process of chem-mech polishing an insulator layer arranged on a semiconductor wafer, wherein the wafer is brought into contact with a rotating polish wheel having a polishing pad disposed thereon, the improvement comprising:
- providing sufficient slurry to form a pool defined by a dam disposed about the outer periphery of the polish wheel, wherein said polishing pad is immersed in said pool during polishing, and wherein said slurry comprises a liquid suspension of solid particulates having a hardness commensurate to the hardness of the insulator layer;
- and
- elevating the temperature of said slurry to at least approximately 85.degree. F.
In a process of chem-mech polishing an insulator layer arranged on a semiconductor wafer, wherein the wafer is brought into contact with a rotating polish wheel having a polishing pad disposed thereon, the improvement comprising:
- providing sufficient slurry to form a pool defined by a dam disposed about the outer periphery of the polish wheel, wherein said polishing pad is immersed in said pool during polishing, and wherein said slurry comprises a suspension of silica particulates having an average size greater than 0.006 microns, said silica particles comprising approximately 10%-15% by weight of said slurry;
- and
- elevating the temperature of said slurry to at least approximately 85.degree. F.
In a process of chem-mech polishing a layer of silicon oxide disposed on a semiconductor substrate, wherein the substrate is supported by a quill in contact with a rotating polish wheel having a polishing pad disposed thereon, the improvement comprising:
- providing an amount of slurry sufficient to form a pool defined by a dam disposed about the polish wheel, wherein said polishing pad is immersed in said pool during polishing, and wherein said slurry comprises a suspension of approximately 10%-15 % silica particulates by weight, said particulates having an average diameter of at least approximately 0.02 microns;
- and
- elevating the temperature of said slurry to at least approximately 85.degree. F.;
- and wherein
- said polish wheel rotates at a speed no greater than approximately 30 RPM.
Dependencies are inferred from the claim text.