Systems and methods for substrate polishing end point detection using improved friction measurement

• US 9,061,394 B2
• Filed: 04/28/2012
• Issued: 06/23/2015
• 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 Chih, Karuppiah, Lakshmanan, Butterfield, Paul D., Rondum, Erik S.
• Primary Examiner(s): Wilson, Lee D
• Assistant Examiner(s): MCDONALD, SHANTESE L
• Application Number:
  US13/459,079
• Publication Number:
  US 20130122788A1
• Time in Patent Office: 1,151 Days
• Field of Search: 451/5, 451/8, 451/21, 451/56, 451/59, 451/443
• US Class Current: 1/1
• 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 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,

wherein the side force measurement instrument includes an arrangement of a plurality of flexures, at least one flexure including a strain gauged coupled thereto, and wherein the plurality of flexures are disposed with a longitudinal dimension aligned to intersect an axis of rotation of the carriages.

2. The apparatus of claim 1 further comprising a spindle adapted to couple the lower carriage to the polishing head.

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

a polishing head assembly 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 head assembly including;

an upper carriage;

a side force measurement instrument coupled to the upper carriage;

a lower carriage coupled to the side force measurement instrument; and

polishing head coupled to the lower carriage and adapted to hold the substrate,

wherein the side force measurement instrument includes an arrangement of a plurality of flexures, at least one flexure including a strain gauged coupled thereto, and wherein the plurality of flexures are disposed with a longitudinal dimension aligned to intersect an axis of rotation of the carriages.

4. The system of claim 3 further comprising a spindle adapted to couple the lower carriage to the polishing head.

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

rotating a platen supporting a polishing pad;

coupling an upper carriage to a lower carriage via a side force measurement instrument, the lower carriage adapted to support a polishing head adapted to hold a substrate, wherein the side force measurement instrument includes an arrangement of a plurality of flexures, at least one flexure including a strain gauged coupled thereto, and wherein the plurality of flexures are disposed with a longitudinal dimension aligned to intersect an axis of rotation of the carriages;

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

measuring an amount of side force on the substrate as the substrate is polished.

6. The method of claim 5 further comprising:

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

7. The method of claim 5 further comprising:

supporting the lower carriage from the upper carriage using the arrangement of flexures wherein the flexures each have a flexible dimension and wherein the arrangement is such that the flexible dimension is aligned tangentially with a rotational direction of the carriages.

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

an upper carriage;

a displacement measurement instrument coupled to the upper carriage;

a lower carriage coupled to the displacement measurement instrument and adapted to support a polishing head, and

an arrangement of a plurality of flexures coupled between the carriages and disposed with a longitudinal dimension aligned to intersect an axis of rotation of the carriages.

9. The apparatus of claim 8 further comprising a spindle adapted to couple the lower carriage to the polishing head.

10. The apparatus of claim 8 wherein the displacement measurement instrument includes a distance sensor.

11. The apparatus of claim 10 wherein the distance sensor is at least one of a capacitive distance sensor, an inductive distance sensor, an eddy current distance sensor, and a laser distance sensor.