Advanced chemical mechanical polishing system with smart endpoint detection
AssigneeNutool, Inc.
InventorsHomayoun Talieh, Bulent M. Basol
Life of this patent
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Abstract
The methods and systems described provide for an in-situ endpoint detection for material removal processes such as chemical mechanical polishing (CMP) performed on a workpiece. In a preferred embodiment, an optical detection system is used to detect endpoint during the removal of planar conductive layers using CMP. An optically transparent polishing belt provides endpoint detection through any spot on the polishing belt. Once endpoint is detected, a signal can be used to terminate or alter a CMP process that has been previously initiated.
Claims19
A polishing apparatus for polishing a workpiece comprising:
- a workpiece holder configured to hold the workpiece;
- a flexible polishing pad configured to be positioned adjacent to a face of the workpiece in order to polish the workpiece with a front side of the polishing pad;
- a platen having a plurality of holes positioned on a back side of the polishing pad and configured to supply and exhaust a fluid through the holes to selectively apply pressure to the polishing pad thereby causing the polishing pad to contact the workpiece with selective pressure;
- a plurality of sensors disposed in the platen and configured to detect a property of the workpiece surface and generate a plurality of sensor signals responsive thereto;
- and
- a fluid controller coupled to the sensors and configured to adjust the fluid pressure based at least in part of the sensor signals.
A method of polishing a workpiece using an apparatus having a flexible polishing pad, a platen with holes therein for supplying and exhausting a fluid to selectively apply pressure on the pad, a plurality of sensors for detecting a property of the workpiece surface and a fluid controller, comprising the steps of:
- holding the workpiece in position adjacent to the pad;
- positioning the pad adjacent to a face of the workpiece in order to polish the workpiece with a front side of the polishing pad;
- supplying and exhausting a fluid through the holes of the platen to selectively apply pressure to the polishing pad thereby causing the polishing pad to contact the workpiece with selective pressure;
- sensing to detect a property of the workpiece surface and generate a plurality of sensor signals responsive thereto;
- and
- adjust the fluid pressure based at least in part of the sensor signals.
A method of polishing a workpiece using an apparatus having a polishing pad, a platen with holes therein for supplying and exhausting a fluid to selectively apply pressure on the pad, comprising the steps of:
- holding the workpiece in position adjacent to the pad;
- positioning the pad adjacent to a face of the workpiece in order to polish the workpiece with a front side of the polishing pad;
- and
- supplying and exhausting a fluid through the holes of the platen to selectively apply pressure to the polishing pad thereby causing the polishing pad to contact the workpiece with selective pressure.
Dependencies are inferred from the claim text.