US 11,780,045 B2
Compensation for substrate doping for in-situ electromagnetic inductive monitoring
Wei Lu, Fremont, CA (US); David Maxwell Gage, Sunnyvale, CA (US); Harry Q. Lee, Los Altos, CA (US); Kun Xu, Sunol, CA (US); and Jimin Zhang, San Jose, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Jun. 13, 2019, as Appl. No. 16/440,785.
Claims priority of provisional application 62/687,712, filed on Jun. 20, 2018.
Prior Publication US 2019/0389028 A1, Dec. 26, 2019
Int. Cl. B24B 37/005 (2012.01); G01B 7/06 (2006.01); B24B 49/10 (2006.01); B24B 37/27 (2012.01)
CPC B24B 37/005 (2013.01) [B24B 37/27 (2013.01); B24B 49/105 (2013.01); G01B 7/10 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of chemical mechanical polishing, comprising:
bringing a substrate having a conductive layer disposed over a semiconductor wafer into contact with a polishing pad;
receiving a base signal value representing a conductivity of the semiconductor wafer;
generating relative motion between the substrate and the polishing pad;
monitoring the substrate with an in-situ electromagnetic induction monitoring system as the conductive layer is polished to generate a sequence of signal values that depend on a thickness of the conductive layer and the conductivity of the semiconductive wafer; and
determining a sequence of thickness values for the conductive layer based on the sequence of signal values, wherein determining the sequence of thickness values including at least partially compensating for a contribution of conductivity of the semiconductor wafer to the signal values using the base signal value.