US 12,403,561 B2
Eddy current monitoring to detect vibration in polishing
Kun Xu, Sunol, CA (US); Patrick A. Higashi, Hacienda Heights, CA (US); Hassan G. Iravani, Sunnyvale, CA (US); Harry Q. Lee, Los Altos, CA (US); Haosheng Wu, San Jose, CA (US); Eric T. Wu, Milpitas, CA (US); Ningzhuo Cui, Santa Clara, CA (US); Jeonghoon Oh, Saratoga, CA (US); Christopher Lai, Santa Clara, CA (US); and Jun Qian, Sunnyvale, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Mar. 9, 2022, as Appl. No. 17/691,101.
Prior Publication US 2023/0286107 A1, Sep. 14, 2023
Int. Cl. B24B 49/10 (2006.01); B24B 37/005 (2012.01); B24B 37/26 (2012.01)
CPC B24B 49/105 (2013.01) [B24B 37/005 (2013.01); B24B 37/26 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A polishing system, comprising:
a rotatable platen to hold a polishing pad;
a carrier head to hold a substrate in contact with the polishing pad;
a motor to rotate the rotatable platen;
an in-situ eddy current monitoring system including a sensor positioned in the rotatable platen such that the sensor sweeps beneath the carrier head with each rotation of the rotatable platen; and
a controller configured to
receive a signal from the in-situ eddy current monitoring system,
select portions of the signal that correspond to off-metal positions of the sensor, the off-metal positions excluding at least positions of the sensor that are below the carrier head,
measure noise in the selected portions of the signal that correspond to the off-metal positions of the sensor, and
compare the measured noise to a threshold value to determine whether to generate an alert.