SYSTEMS AND METHODS FOR SUBSTRATE POLISHING END POINT DETECTION USING IMPROVED FRICTION MEASUREMENT

• US 20130122782A1
• Filed: 04/27/2012
• Published: 05/16/2013
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chang, Shou-Sung, Chen, Hung, Karuppiah, Lakshmanan, Butterfield, Paul D., Rondum, Erik S.
• Granted Patent: US 9,862,070 B2
• Time in Patent Office: Days
• US Class Current: 451/8
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B24B 49/16 taking regard of the load

Abstract

Methods, apparatus, and systems for polishing a substrate are provided. The invention includes an upper platen; a torque/strain measurement instrument coupled to the upper platen; and a lower platen coupled to the torque/strain measurement instrument and adapted to drive the upper platen to rotate through the torque/strain measurement instrument. In other embodiments, the invention includes an upper carriage; a side force measurement instrument coupled to the upper carriage; and a lower carriage coupled to the side force measurement instrument and adapted to support a polishing head. Numerous additional aspects are disclosed.

Claims

1. An apparatus for polishing a substrate, the apparatus comprising:

an upper platen;

a torque/strain measurement instrument coupled to the upper platen; and

a lower platen coupled to the torque/strain measurement instrument and adapted to drive the upper platen to rotate through the torque/strain measurement instrument.

2. The apparatus of claim 1 further comprising a support adapted to support the upper platen on the lower platen.

3. The apparatus of claim 2 wherein the support includes a flexure.

4. The apparatus of claim 2 wherein the support includes a bearing.

5. The apparatus of claim 1 further comprising a coupling adapted to couple the torque/strain measurement instrument to the upper platen.

6. The apparatus of claim 1 wherein the torque/strain measurement instrument is a torque sensor.

7. The apparatus of claim 1 wherein the torque/strain measurement instrument is a load cell.

8. A system for chemical-mechanical planarization processing of substrates, the system comprising:

a polishing head adapted to hold a substrate; and

a polishing pad support adapted to hold and rotate a polishing pad against the substrate held in the polishing head, the polishing pad support including;

an upper platen;

a torque/strain measurement instrument coupled to the upper platen; and

a lower platen coupled to the torque/strain measurement instrument and adapted to drive the upper platen to rotate through the torque/strain measurement instrument.

9. The system of claim 8 further comprising a support adapted to support the upper platen on the lower platen.

10. The system of claim 9 wherein the support includes a flexure.

11. The system of claim 9 wherein the support includes a bearing.

12. The system of claim 8 further comprising a coupling adapted to couple the torque/strain measurement instrument to the upper platen.

13. The system of claim 8 wherein the torque/strain measurement instrument is a torque sensor.

14. The system of claim 8 wherein the torque/strain measurement instrument is a load cell.

15. A method of polishing a substrate, the method comprising:

coupling a lower platen to an upper platen via a torque/strain measurement instrument, the upper platen adapted to hold a polishing pad;

rotating the lower platen to drive the upper platen;

applying a polishing head holding a substrate to the polishing pad on the upper platen; and

measuring an amount of torque needed to rotate the upper platen as the substrate is polished.

16. The method of claim 15 further comprising:

detecting a polishing end point based upon detecting a change in the measured amount of torque relative to a threshold.

17. The method of claim 15 wherein the torque is measured using a torque sensor.

18. The method of claim 15 wherein the torque is measured using a load cell.

19. The method of claim 15 further comprising:

supporting the upper platen on the lower platen using a bearing.

20. The method of claim 15 further comprising:

supporting the upper platen on the lower platen using an arrangement of flexures.