Apparatus and method for performing end point detection on a linear planarization tool
AssigneeLam Research Corporation
InventorsBrian Thornton, Andrew J. Nagengast, Robert G. Boehm, Jr., Anil K. Pant, Wilbur C. Krusell
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Abstract
A technique for utilizing a sensor to monitor fluid pressure from a fluid bearing located under a polishing pad to detect a polishing end point. A sensor is located at the leading edge of a fluid bearing of a linear polisher, which is utilized to perform chemical-mechanical polishing on a semiconductor wafer. The sensor monitors the fluid pressure to detect a change in the fluid pressure during polishing, which change corresponds to a change in the shear force when the polishing transitions from one material layer to the next.
Claims30
In a tool utilized to polish a material having a planar surface and in which the planar surface is placed upon a polishing pad for polishing the planar surface, an apparatus for determining a polishing end point for polishing the planar surface comprising:
- a fluid bearing disposed along an underside of the pad opposite the surface for dispensing fluid between said fluid bearing and the pad;
- a sensor coupled to said fluid bearing to measure a pressure change of the fluid when the end point for polishing the planar surface is reached;
- a monitor coupled with the sensor and operative to determine that the end point for polishing the planar surface is reached based on the pressure change measured by the sensor.
In a linear polisher for performing chemical-mechanical polishing (CMP) on a surface of a substrate or a surface of a layer formed on the substrate, and in which the surface is placed upon a linearly moving polishing pad for polishing the surface, an apparatus for determining a polishing end point for polishing the surface comprising:
- a fluid bearing disposed along an underside of a linearly moving belt having the pad disposed thereon, said fluid bearing for dispensing fluid along a gap between the fluid bearing and the underside of the belt;
- a sensor coupled to said fluid bearing to measure a pressure change of the fluid when the end point for polishing the surface is reached;
- a monitor coupled with the sensor and operative to determine that the end point for polishing the surface is reached based on the pressure change measured by the sensor.
In a linear polisher for performing chemical-mechanical polishing (CMP) on a first material layer formed on a semiconductor wafer, and in which the first material layer is polished to expose an underlying second material layer, an apparatus for determining a polishing end point for stopping the polishing when the second material layer is exposed comprising:
- a fluid bearing disposed along an underside of a linearly moving belt having the pad disposed thereon, said fluid bearing for dispensing fluid along a gap between the fluid bearing and the underside of the belt;
- a sensor coupled to said fluid bearing to measure a pressure change of the fluid when the end point for polishing the first material layer is reached;
- a monitor coupled with the sensor and operative to determine that the end point for polishing the first material layer is reached based on the pressure change measured by the sensor.
A method of determining a polishing end point for polishing a surface, comprising:
- dispensing fluid along an underside of a pad or a belt upon which the pad is mounted opposite the surface being polished;
- polishing the surface;
- measuring a pressure change of the fluid when an end point for polishing the surface is reached;
- determining that the end point for polishing the surface is reached by monitoring the measured pressure change.
In a linear polisher for performing chemical-mechanical polishing (CMP) on a first material layer formed on a semiconductor wafer, and in which the first material layer is polished to expose an underlying second material layer, a method of determining a polishing end point for stopping the polishing when the second material layer is exposed, comprising the steps of:
- dispensing fluid along an underside of a pad or a belt upon which the pad is mounted opposite the wafer being polished;
- polishing the first material layer;
- measuring a pressure change of the fluid at an end point for polishing the first material layer when the second material layer is exposed.
In a linear polisher for performing chemical-mechanical polishing (CMP) on a surface of a substrate or a surface of a layer formed on the substrate, and in which the surface is placed upon a linearly moving polishing pad for polishing the surface, an apparatus for determining a polishing end point for polishing the surface comprising:
- a fluid bearing disposed along an underside of a linearly moving belt having the pad disposed thereon, said fluid bearing for dispensing fluid along a gap between the fluid bearing and the underside of the belt;
- a sensor coupled to said fluid bearing to measure a pressure change of the fluid when the end point for polishing the surface is reached;
- wherein the surface is polished to expose an underlying material and in which the end point is reached when the underlying material is exposed;
- wherein said sensor is located at a leading edge of said fluid bearing where a point on the pad first makes contact with said fluid bearing.
In a linear polisher for performing chemical-mechanical polishing (CMP) on a first material layer formed on a semiconductor wafer, and in which the first material layer is polished to expose an underlying second material layer, an apparatus for determining a polishing end point for stopping the polishing when the second material layer is exposed comprising:
- a fluid bearing disposed along an underside of a linearly moving belt having the pad disposed thereon, said fluid bearing for dispensing fluid along a gap between the fluid bearing and the underside of the belt;
- a sensor coupled to said fluid bearing to measure a pressure change of the fluid when the end point for polishing the first material layer is reached;
- wherein the pressure change is a result of a change in a shear force exerted at an interface of the pad and the first material layer and the shear force changes when the pad begins to polish the second material layer;
- wherein said sensor is located at a leading edge of said fluid bearing where a point on the pad first makes contact with said fluid bearing.
Dependencies are inferred from the claim text.