Apparatus for interlayer planarization of semiconductor material
Patent 5257478 Issued on November 2, 1993. Estimated Expiration Date: 
January 31, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 31, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3499250 3504457 Workpiece holder for polishing operation Integrated circuit planarization by mechanical polishing Patent #: 4879258 InventorsAssigneeApplicationNo. 829736 filed on 01/31/1992US Classes:451/287, Planar surface abrading51/297, LAMINATING451/533LaminateExaminersPrimary: Kisliuk, Bruce M.Assistant: Reichenbach, Bryan Attorney, Agent or FirmInternational ClassesB24B 007/22B24B 001/00 AbstractA pad for planarizing the surface of a semiconductor wafer. The pad includes at least two layers. One layer has a hydrostatic modulus which is different from the hydrostatic modulus of the other pad. | |
