Endpoint detection apparatus and method for chemical/mechanical polishing
January 30, 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 3874959 Polishing apparatus Method of controlling a plasma etching process by monitoring the impedance changes of the RF power Monitoring technique for plasma etching In situ conductivity monitoring technique for chemical/mechanical planarization endpoint detection Wafer flood polishing Method of etching back of tungsten layers on semiconductor wafers, and solution therefore Method of endpoint detection during chemical/mechanical planarization of semiconductor wafers In situ monitoring technique and apparatus for chemical/mechanical planarization endpoint detection Method of chemical-mechanical polishing an electronic component substrate and polishing slurry therefor InventorsApplicationNo. 828054 filed on 01/30/1992US Classes:216/86, By electrical means or of an electrical property51/307, WITH INORGANIC MATERIAL216/88, Using film of etchant between a stationary surface and a moving surface (e.g., chemical lapping, etc.)257/E21.244, Involving dielectric removal step (EPO)438/693, Utilizing particulate abradant451/41Glass or stone abradingExaminersPrimary: Hearn, Brian E.Assistant: Holtzman, Laura M. Attorney, Agent or FirmInternational ClassH01L 021/304AbstractAn apparatus and method for determining a selected endpoint in the polishing of layers on a workpiece in a chemical/mechanical polishing apparatus where the workpiece is rotated by a motor against a polishing pad. When a difficult to polish layer, i.e., one requiring a chemical change in a surface skin of the layer which skin is then abraded away by a mechanical process is removed from a more easy to polish surface, i.e., one that relies solely on mechanical abrasion and does not need to have a chemically converted skin thereon. The power required to maintain a set rotational speed in a motor rotating the workpiece significantly drops when the difficult to polish layer is removed. This current drop is used to detect the point at which the polishing must be stopped to avoid over polishing effects, i.e., dishing or thinning or removal of the more easily removed underlying material. Thus, an end point in the process can be established.Other References
Field of SearchWITH INORGANIC MATERIAL | |
