In-situ endpoint detect for non-transparent polishing member
AssigneeASM Nutool, Inc.
InventorsMukesh Desai, Yuchun Wang, Efrain Velazquez
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Abstract
A sensing apparatus for detecting a processing endpoint of a multi-layer semiconductor wafer includes a light source to emit light against a surface of the semiconductor wafer, a color sensor to sense a reflection color from the surface of the semiconductor wafer in response to the incident light and to generate a sensor signal, and a decision circuit coupled to the color sensor and configured to decide whether the wafer processing endpoint has been reached based at least in part on the sensor signal. In another embodiment, a sensing apparatus is coupled to a movable structure to position the sensing apparatus to sense the surface of the semiconductor wafer.
Claims26
A sensing apparatus for detecting a processing endpoint of a multi-layer semiconductor wafer comprising:
- a light source to emit incident light against a surface of the semiconductor wafer;
- a color sensor to sense a reflection color from the surface of the semiconductor wafer in response to the incident light and to generate a sensor signal;
- and
- a decision circuit coupled to the color sensor and configured to decide whether the wafer processing endpoint has been reached based at least in part on the sensor signal.
An endpoint detection system for detecting a processing endpoint of a multi-layer semiconductor wafer comprising:
- a light source to emit incident light against a surface of the semiconductor wafer;
- a color sensor to sense a reflection color from the surface of the semiconductor wafer in response to the incident light and to generate a sensor signal;
- a movable structure coupled to the light source and the color sensor to position the color sensor to sense the reflection color;
- a comparator coupled to the color sensor to compare the sensor signal against a signal based upon a threshold reflection color;
- and
- a decision circuit coupled to the comparator to decide whether the wafer processing endpoint has been reached based at least in part on reflection color comparison data generated by the comparator.
An endpoint detection system for detecting a processing endpoint of a semiconductor wafer comprising:
- a sensing apparatus configured to sense a metric related to a surface of the semiconductor wafer and to generate a sensor signal based upon the metric;
- a decision circuit coupled to the sensing apparatus and configured to decided whether the wafer processing endpoint has been reached based at least in part on the sensor signal;
- and
- a movable structure coupled to the sensing apparatus to position the sensing apparatus to sense the metric.
A method for detecting a processing endpoint of a multi-layer semiconductor wafer comprising:
- emitting incident light against a surface of the semiconductor wafer;
- sensing a reflection color from the surface of the semiconductor wafer in response to the incident light;
- generating a sensor signal based upon the sensing of the reflection color;
- and
- determining whether the wafer processing endpoint has been reached based at least in part on the sensor signal.
A method for detecting a processing endpoint of a multi-layer semiconductor wafer in a chemical mechanical polishing (CMP) apparatus having a carrier head and a polishing member, and wherein the semiconductor wafer is attached to the carrier head, the method comprising the steps of:
- stopping polishing of the semiconductor wafer;
- removing the semiconductor wafer from contact with the polishing member by elevating the carrier head;
- moving a sensing apparatus underneath a bottom surface of the semiconductor wafer;
- emitting incident light from the sensing apparatus against the bottom surface of the semiconductor wafer;
- sensing the reflection color from the bottom surface of the semiconductor wafer with the sensing apparatus in response to the incident light;
- and
- determining whether to continue with the polishing of the semiconductor wafer based at least in part on the reflection color.
Dependencies are inferred from the claim text.