Chemical mechanical polishing system and method of using

Patent metadata

Field	Value
Publication number	US-11724360-B2
Application number	US-202016910978-A
Country	US
Kind code	B2
Filing date	Jun 24, 2020
Priority date	May 29, 2020
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

A method of conditioning a polishing pad includes receiving information on a roughness of the polishing pad from a first sensor. The method further includes conditioning the polishing pad using a conditioner. The method further includes detecting the roughness of the polishing pad following the conditioning. The method further includes repeating the conditioning in response to the detected roughness of the polishing pad being outside of a threshold roughness range.

First claim

What is claimed is:

1. A method of conditioning a polishing pad comprising:
performing a chemical mechanical polishing (CMP) process using the polishing pad;
receiving information on a roughness of the polishing pad from a first sensor;
conditioning the polishing pad using a conditioner;
detecting the roughness of the polishing pad following the conditioning;
tracking a number of iterations of the conditioning; and
outputting a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit; and
repeating the conditioning in response to the detected roughness of the polishing pad being outside of a threshold roughness range, wherein repeating the conditioning comprises continuing the CMP process during the repeating the conditioning.

2. The method of claim 1 ,
wherein outputting the signal for replacing the polishing pad comprises outputting the signal in response to the number of iterations exceeding a value ranging from 3 to 5.

3. The method of claim 1 , further comprising:
receiving information on the roughness of the polishing pad from a second sensor, wherein the second sensor is configured detect the roughness at a location different from the first sensor; and
determining a roughness profile of the polishing pad based on the information received from the first sensor and the second sensor.

4. The method of claim 3 , further comprising adjusting a location of the conditioner relative to the polishing pad based on the determined roughness profile.

5. The method of claim 4 , wherein adjusting the location of the conditioner comprises moving the conditioner in a direction parallel to a top surface of the polishing pad.

6. The method of claim 1 , further comprising adjusting a pressure exerted on the polishing pad by the conditioner based on information received from the first sensor.

7. The method of claim 6 , wherein adjusting the pressure comprises moving the conditioner in a direction perpendicular to a top surface of the polishing pad.

8. The method of claim 1 , wherein conditioning the polishing pad comprises conditioning the polishing pad during a chemical mechanical polishing (CMP) process.

9. The method of claim 1 , wherein conditioning the polishing pad comprises conditioning the polishing pad after a CMP process.

10. The method of claim 1 , wherein receiving the information on the roughness comprises receiving the information on the roughness during a CMP process.

11. A chemical mechanical polishing (CMP) system comprising:
a polishing pad configured to polish a wafer;
a first sensor configured to detect a roughness of the polishing pad;
a conditioner configured to adjust the roughness of the polishing pad; and
a controller configured to control the conditioner based on information received from the first sensor, wherein the controller is configured to:
track a number of iterations of a conditioning process performed by the conditioner on the polishing pad, and
generate a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit.

12. The CMP system of claim 11 , wherein the first sensor is an optical sensor.

13. The CMP system of claim 11 , further comprising a second sensor configured to detect the roughness of the polishing pad, wherein the second sensor positioned over a different portion of the polishing pad than the first sensor.

14. The CMP system of claim 13 , wherein the controller is configured to determine a roughness profile of the polishing pad based on information from the first sensor and from the second sensor.

15. The CMP system of claim 14 , wherein the controller is configured to control the conditioner based on the determined roughness profile.

16. The CMP system of claim 15 , wherein the controller is configured to control a location of the conditioner relative to the polishing pad based on the determined roughness profile.

17. The CMP system of claim 11 , wherein the controller is configured to control a pressure exerted on the polishing pad by the conditioner based on the information received from the first sensor.

18. The CMP system of claim 11 , wherein the controller is configured to track the number of iterations of the conditioning process.

19. A chemical mechanical polishing (CMP) system comprising:
a polishing head configured to hold a wafer during a CMP process;
a polishing pad configured to polish the wafer;
a plurality of sensors configured to detect a roughness of the polishing pad;
a conditioner configured to adjust the roughness of the polishing pad; and
a controller configured to control the conditioner based on information received from the plurality of sensors, wherein the controller is configured to:
track a number of iterations of the conditioning;
output a signal for replacing the polishing pad in response to the number of iterations reaching an iteration limit,
control a location of the conditioner relative to the polishing pad, and
control a pressure exerted on the polishing pad by the conditioner.

20. The CMP system of claim 19 , wherein a first sensor of the plurality of sensors is configured to emit light toward the polishing pad, and a second sensor of the plurality of sensors is configured to receive the emitted light reflected from the polishing pad.

Assignees

• Taiwan Semiconductor Mfg Co Ltd
• Tsmc Nanjing Company Ltd

Inventors

• Kung Wen Yen

Classifications

• B24B53/017 Primary

  Devices or means for dressing, cleaning or otherwise conditioning lapping tools · CPC title

• B24B37/20

  Lapping pads for working plane surfaces · CPC title

• B24B53/013

  Application of loose grinding agent as auxiliary tool during truing operation · CPC title

• B24B37/005 Primary

  Control means for lapping machines or devices · CPC title

• B24B49/12 Primary

  involving optical means · CPC title