	US 12,420,373 B2
	Control of processing parameters during substrate polishing using cost function
Benjamin Cherian, San Jose, CA (US); and Sivakumar Dhandapani, 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. 28, 2022, as Appl. No. 17/683,054.
Claims priority of provisional application 63/157,508, filed on Mar. 5, 2021.
Prior Publication US 2022/0281055 A1, Sep. 8, 2022
Int. Cl. B24B 37/005 (2012.01)

CPC B24B 37/005 (2013.01)

20 Claims

1. A computer program product for controlling a polishing system comprising a non-transitory computer readable medium comprising instructions for causing one or more computers to:

receive from an in-situ monitoring system, for each region of a plurality of regions on a substrate being processed by the polishing system, a sequence of characterizing values for the region;

for each region, determine a polishing rate for the region;

for each particular parameter update time of a plurality of parameter update times, calculate an adjustment for at least one polishing control parameter of the polishing system, wherein calculating the adjustment includes minimizing a cost function that includes, for each region

i) a difference between a current characterizing value or an expected characterizing value at an expected endpoint time and a target characterizing value for the region, and

ii) a plurality of projected future pressure changes to occur at parameter update times subsequent to the particular parameter update time for the region and/or a plurality of differences between projected future pressures to occur at parameter update times subsequent to the particular parameter update time and a baseline pressure for the region; and

for each particular parameter update time, adjust to the at least one polishing control parameter of the polishing system based on the calculated adjustment.