US 12,487,566 B2
Polishing semiconductor wafers using causal models
Brian E. Brooks, St. Paul, MN (US); Gilles J. Benoit, Minneapolis, MN (US); Peter O. Olson, Andover, MN (US); Tyler W. Olson, Woodbury, MN (US); Himanshu Nayar, St. Paul, MN (US); Frederick J. Arsenault, Stillwater, MN (US); Nicholas A. Johnson, Burnsville, MN (US); Vincent J. Laraia, Houlton, WI (US); and Don V. West, St. Paul, MN (US)
Assigned to 3M Innovative Properties Company, St. Paul, MN (US)
Appl. No. 17/438,027
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Oct. 3, 2019, PCT No. PCT/IB2019/058438
§ 371(c)(1), (2) Date Sep. 10, 2021,
PCT Pub. No. WO2020/188338, PCT Pub. Date Sep. 24, 2020.
Claims priority of provisional application 62/898,938, filed on Sep. 11, 2019.
Claims priority of provisional application 62/818,816, filed on Mar. 15, 2019.
Prior Publication US 2022/0146991 A1, May 12, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G05B 19/418 (2006.01); B24B 37/005 (2012.01); G05B 13/02 (2006.01); H01L 21/461 (2006.01); H01L 21/66 (2006.01)
CPC G05B 13/028 (2013.01) [B24B 37/005 (2013.01); H01L 21/461 (2013.01); H01L 22/12 (2013.01); H01L 22/20 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
repeatedly performing the following:
selecting a configuration of input settings for polishing a semiconductor wafer, based on a causal model mapped to a distribution over possible control settings such that the causal model measures current causal relationships between input settings and a quality of semiconductor wafers, wherein control settings are assigned to different procedural instances that allow blocked groups to later be identified in order to compute impact measurements between blocked groups, wherein probability matching is utilized to map the impact measurements and confidence intervals in the causal model to probabilities and the control settings are assigned based on these probabilities;
receiving a measure of the quality of the semiconductor wafer polished with the configuration of input settings;
adjusting, based on the measure of the quality of the semiconductor wafer polished with the configuration of input settings, the causal model; and
re-computing the causal model by computing overall impact measurements based on confidence intervals around the overall impact measurements and means of d-scores.