Adaptive endpoint method for pad life effect on chemical mechanical polishing
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChu-An Lee, Hui-Chi Huang, Peng-Chung Jangjian
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Abstract
The present disclosure provides a chemical mechanical polishing (CMP) system. The CMP system includes a pad designed for wafer polishing, a motor driver coupled with the pad and designed to drive the pad during the wafer polishing, and a controller coupled with the motor driver and designed to control the motor driver. The CMP system further includes an in-situ rate monitor designed to collect polishing data from a wafer on the pad, determine CMP endpoint based on a life stage of the pad, and provide the CMP endpoint to the controller.
Claims20
A chemical mechanical polishing (CMP) system, comprising:
- a pad designed for wafer polishing;
- a motor driver coupled with the pad and designed to drive the pad during the wafer polishing;
- a controller coupled with the motor driver and designed to control the motor driver;
- and
- an in-situ rate monitor including a signal module designed to extract a polishing signal during the wafer polishing, wherein the in-situ rate monitor is designed to amplify the polishing signal according to a life stage of the pad, determine CMP endpoint based on the life stage of the pad, and provide the CMP endpoint to the controller.
A chemical mechanical polishing (CMP) system, comprising:
- a polishing pad configured to polish a wafer;
- a motor driver coupled with the polishing pad and configured to drive the polishing pad during wafer polishing;
- an in-situ rate monitor configured to define a time region of pad life for the polishing pad and configured to assign a ladder coefficient to the polishing pad according to the time region of pad life;
- and
- a controller coupled with the motor driver and in-situ rate monitor and configured to control the motor driver to apply a CMP process to the wafer positioned on the polishing pad and control the motor driver to end the CMP process at an endpoint according to the time region of pad life for the polishing pad.
A chemical mechanical polishing (CMP) system, comprising:
- a polishing pad configured to polish a wafer;
- a motor driver coupled with the polishing pad and configured to drive the polishing pad during wafer polishing;
- an in-situ rate monitor configured to:
- define a plurality of time regions of pad life for the polishing pad;
- assign a ladder coefficient to the polishing pad according to the plurality of time regions of pad life;
- define a plurality of endpoint windows to the plurality of time regions, respectively, according to pad life effect;
- determine a time region of a polishing signal of the wafer based on the ladder coefficient;
- and
- associate one of the endpoint windows to the polishing signal according to the time region;
- and
- a controller coupled with the motor driver and in-situ rate monitor and configured to control the motor driver to apply a CMP process to the wafer positioned on the polishing pad and control the motor driver to end the CMP process at an endpoint determined by the endpoint window associated with the polishing signal.
Dependencies are inferred from the claim text.