US 11,939,491 B2
Method of polishing object to be polished containing material having silicon-silicon bond
Kohsuke Tsuchiya, Kiyosu (JP); Maki Asada, Kiyosu (JP); and Satoshi Momota, Kiyosu (JP)
Assigned to FUJIMI INCORPORATED, Kiyosu (JP)
Appl. No. 17/441,587
Filed by FUJIMI INCORPORATED, Kiyosu (JP)
PCT Filed Jan. 30, 2020, PCT No. PCT/JP2020/003548
§ 371(c)(1), (2) Date Sep. 21, 2021,
PCT Pub. No. WO2020/195149, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 2019-061177 (JP), filed on Mar. 27, 2019; and application No. 2019-061187 (JP), filed on Mar. 27, 2019.
Prior Publication US 2022/0186077 A1, Jun. 16, 2022
Int. Cl. C09G 1/02 (2006.01); H01L 21/306 (2006.01)
CPC C09G 1/02 (2013.01) [H01L 21/30625 (2013.01)] 12 Claims
 
1. A method of polishing an object to be polished containing a material having a silicon-silicon bond, the polishing method comprising a final polishing step Pf,
wherein the final polishing step Pf has a plurality of polishing sub-steps,
the plurality of polishing sub-steps are continuously performed on the same polishing platen,
a final polishing sub-step in the plurality of polishing sub-steps is a polishing sub-step Pff of polishing using a polishing composition Sff,
a polishing sub-step provided before the polishing sub-step Pff in the plurality of polishing sub-steps is a polishing sub-step Pfp of polishing using a polishing composition Sfp, and
the polishing composition Sff satisfies at least one of the following condition (A) or the following condition (B):
condition (A): a value of a haze parameter of the polishing composition Sff obtained in a standard test 1 is smaller than a value of the haze parameter of the polishing composition Sfp obtained in the standard test 1, and
condition (B): the polishing composition Sff contains an abrasive Aff, a basic compound Bff, and hydroxyethyl cellulose; and
wherein the method satisfies at least one selected from the group consisting of (a), (b), and (c):
(a) R1fp/R2fp is 1.25 or less, wherein:
R1fp, is D90 of particles present in the polishing composition Sfp, measured by a dynamic light scattering method; and
R2fp is D90 of the particles present in the polishing composition Sfp after adjusting the pH to 12.5 using potassium hydroxide and stirring for 30 minutes, measured by the dynamic light scattering method;
(b) R1ff/R2ff is more than 1.25, wherein:
R1ff is D90 of particles present in the polishing composition Sff, measured by the dynamic light scattering method; and
R2ff is D90 of the particles present in the polishing composition Sff after adjusting the pH to 12.5 using potassium hydroxide and stirring for 30 minutes, measured by the dynamic light scattering method; and
(c) the polishing method further comprises a preliminary polishing step Pp before the final polishing step Pf, wherein:
the preliminary polishing step Pp is a step of polishing using the polishing composition Sp in which a polishing removal rate obtained in a standard test 2 is 50 nm/min or more;
the final polishing step Pf is a step of polishing using the polishing composition Sf in which the polishing removal rate obtained in the standard test 2 is more than 0 nm/min and less than 50 nm/min; and
both the polishing composition Sff and the polishing composition SI correspond to the polishing composition Sf, and
R1p/R2p is 1.25 or less, wherein:
R1p is D90 of particles present in the polishing composition Sp, measured by the dynamic light scattering method; and
R2p is D90 of the particles present in the polishing composition Sp after adjusting the pH to 12.5 using potassium hydroxide and stirring for 30 minutes, measured by the dynamic light scattering method.