US 12,440,942 B2
Pressure signals with different frequencies during friction monitoring to provide spatial resolution
Thomas Li, Santa Clara, CA (US); and Benjamin Cherian, San Jose, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Feb. 22, 2022, as Appl. No. 17/677,895.
Claims priority of provisional application 63/155,917, filed on Mar. 3, 2021.
Prior Publication US 2022/0281060 A1, Sep. 8, 2022
Int. Cl. B24B 37/013 (2012.01); B24B 37/04 (2012.01); H01L 21/66 (2006.01)
CPC B24B 37/013 (2013.01) [B24B 37/042 (2013.01); H01L 22/26 (2013.01)] 21 Claims
OG exemplary drawing
 
13. A method of polishing, comprising:
holding a substrate with a carrier head against a polishing surface of a polishing pad;
generating relative motion between the substrate and polishing pad;
applying a first pressure in a first cyclic waveform having a first frequency to a first region of the substrate applying a second pressure in a second cyclic waveform having a different second frequency to a different second region of the substrate;
during polishing of the substrate, monitoring the substrate with an in-situ motor torque monitoring system to generate a sequence of measured values; and
determining a relative contribution to the sequence of measured values from the first region and second region based on distinguishing the first frequency from the second frequency.