Prosecution Insights
Last updated: April 19, 2026
Application No. 18/122,961

SULFONIC ACID-MODIFIED COLLOIDAL SILICA

Final Rejection §103
Filed
Mar 17, 2023
Examiner
CULBERT, ROBERTS P
Art Unit
1716
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Fujimi Incorporated
OA Round
2 (Final)
82%
Grant Probability
Favorable
3-4
OA Rounds
2y 5m
To Grant
78%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
659 granted / 809 resolved
+16.5% vs TC avg
Minimal -4% lift
Without
With
+-3.6%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
20 currently pending
Career history
829
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
42.6%
+2.6% vs TC avg
§102
35.1%
-4.9% vs TC avg
§112
9.4%
-30.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 809 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Arguments Applicant’s arguments with respect to claims as amended have been fully considered. Applicant has argued that the references do not teach silica preferably has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. However, according to the description (Pages 10-11) the microparticles are reduced as claimed by the solvent distillation step. Therefore, the same distillation step of Fei et al. (Examples 1, 3, 6) would reasonably be expected to reduce the microparticles as claimed, or else is the result of essential limitations which have not been claimed. Further, the same distillation step of Otsuki et al. (Paragraphs 96, 105 and Examples) would reasonably be expected to reduce the microparticles as claimed, or else is the result of essential limitations which have not been claimed. Further, Otsuki et al. (Paragraphs 103, 105) ultrafiltration which would reasonably be expected to reduce microparticles as claimed, or else is the result of essential limitations which have not been claimed Additionally, newly cited Ashitaka et al. teaches (Paragraphs 13 and 33) silane modified colloidal silica preferably has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the polishing silica of Fei et al. and Otsuki et al. with a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size in order to produce chemical mechanical polishing particles with predictable results. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claims 1 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over CN 112429741 to Fei et al. Regarding Claims 1 and 2, Fei et al. teaches sulfonic acid modified colloidal silica wherein during synthesis the mercapto-containing silane coupling agent is present at 0.01 to 10% of the mass of silica in the silica sol to me modified (See Claim 2). Fei et al. teaches (Examples 1-6) applying different concentrations of mercaptopropyltrimethoxysilane to the silica sol and prepared by the preparation method of mixing with alcohol solvent, heating, refluxing and aging, followed by heating, mixing with oxidizing agent and reacting. Therefore, it is implicit that the amount of sulfonic acid groups per 1g of particles is 3.0 µmol/g or more and 10.5 µmol/g or less. Regarding Claim 1, Fei et al. teaches silica particles are widely used for chemical mechanical polishing, but does not expressly teach the sulfonic acid-modified colloidal silica has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. However, according to the description (Pages 10-11) the microparticles are reduced as claimed by the solvent distillation step. Therefore, the same distillation step of Fei et al. (Examples 1, 3, 6) would reasonably be expected to reduce the microparticles as claimed, or else is the result of essential limitations which have not been claimed. Claims 1 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over CN 112429741 to Fei et al. in view of US Publication 2017/0362465 to Ashitaka et al. Regarding Claims 1 and 2, Fei et al. teaches sulfonic acid modified colloidal silica wherein during synthesis the mercapto-containing silane coupling agent is present at 0.01 to 10% of the mass of silica in the silica sol to me modified (See Claim 2). Fei et al. teaches (Examples 1-6) applying different concentrations of mercaptopropyltrimethoxysilane to the silica sol and prepared by the preparation method of mixing with alcohol solvent, heating, refluxing and aging, followed by heating, mixing with oxidizing agent and reacting. Therefore, it is implicit that the amount of sulfonic acid groups per 1g of particles is 3.0 µmol/g or more and 10.5 µmol/g or less. Regarding Claim 1, Fei et al. teaches silica particles are widely used for chemical mechanical polishing, but does not expressly teach the sulfonic acid-modified colloidal silica has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. However, Ashitaka et al. teaches (Paragraphs 13 and 33-37) silane modified colloidal silica preferably has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the silica of Fei et al. with a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size in order to produce chemical mechanical polishing particles with predictable results. Claims 1 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over US Publication 2022/0177318 to Otsuki et al. Regarding Claims 1 and 2, Otsuki et al. teaches (See at least Paragraphs 110- 116 in context) sulfonic acid modified colloidal silica wherein the amount of sulfonic acid groups per 1g of particles is 0.5 to 350 µmol/g, preferably 5.5 to 170 µmol/g. It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide a sulfonic acid modified colloidal silica wherein the amount of sulfonic acid groups per 1g of particles is 3.0 µmol/g or more and 10.5 µmol/g or less in order to provide a modified colloidal silica that can be stably dispersed and can further increase electrostatic attraction or repulsion against a polished object, and further suppresses an increase in secondary particle size, formation of aggregates, and gelation as recited by Otsuki et al. Regarding Claim 1, Otsuki et al. does not expressly teach the sulfonic acid-modified colloidal silica has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. However, according to the description (Pages 10-11) the microparticles are reduced as claimed by the solvent distillation step. Therefore, the same distillation step of Otsuki et al. (Paragraphs 96, 105 and Examples) would reasonably be expected to reduce the microparticles as claimed, or else is the result of essential limitations which have not been claimed. Further, Otsuki et al. (Paragraphs 103, 105) ultrafiltration which would reasonably be expected to reduce microparticles as claimed, or else is the result of essential limitations which have not been claimed. Claims 1 and 2 are rejected under 35 U.S.C. 103 as being unpatentable over US Publication 2022/0177318 to Otsuki et al. in view of US Publication 2017/0362465 to Ashitaka et al. Regarding Claims 1 and 2, Otsuki et al. teaches (See at least Paragraphs 110- 116 in context) sulfonic acid modified colloidal silica wherein the amount of sulfonic acid groups per 1g of particles is 0.5 to 350 µmol/g, preferably 5.5 to 170 µmol/g. It would have been obvious to one of ordinary skill in the art at the time of the claimed invention to provide a sulfonic acid modified colloidal silica wherein the amount of sulfonic acid groups per 1g of particles is 3.0 µmol/g or more and 10.5 µmol/g or less in order to provide a modified colloidal silica that can be stably dispersed and can further increase electrostatic attraction or repulsion against a polished object, and further suppresses an increase in secondary particle size, formation of aggregates, and gelation as recited by Otsuki et al. Regarding Claim 1, Otsuki et al. teaches silica particles are used as abrasive for electronic materials such as semiconductor wafers (Paragraph 3), but does not expressly teach the sulfonic acid-modified colloidal silica has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. However, Ashitaka et al. teaches (Paragraphs 13 and 33-37) silane modified colloidal silica for polishing preferably has a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size based on a Heywood diameter (diameter of the equivalent circle) by image analysis using a scanning electron microscope. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the silica of Ashitaka et al. with a number-based percentage of 10% or less of microparticles having a particle size of 40% or less of a volume-average particle size in order to produce chemical mechanical polishing particles with predictable results. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Roberts P Culbert whose telephone number is (571)272-1433. The examiner can normally be reached Monday thru Thursday 7:30 AM-6 PM EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Parviz Hassanzadeh can be reached at 571-272-1435. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /ROBERTS P CULBERT/Primary Examiner, Art Unit 1716
Read full office action

Prosecution Timeline

Mar 17, 2023
Application Filed
Jul 04, 2025
Non-Final Rejection — §103
Jan 07, 2026
Response Filed
Mar 14, 2026
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12598928
APPARATUS AND METHODS FOR SELECTIVELY ETCHING SILICON OXIDE FILMS
2y 5m to grant Granted Apr 07, 2026
Patent 12584039
SLURRY COMPOSITION FOR A CHEMICAL MECHANICAL POLISHING
2y 5m to grant Granted Mar 24, 2026
Patent 12577466
PHOTORESIST DEVELOPMENT WITH ORGANIC VAPOR
2y 5m to grant Granted Mar 17, 2026
Patent 12575352
ETCHING METHOD AND ETCHING APPARATUS
2y 5m to grant Granted Mar 10, 2026
Patent 12575353
METHOD FOR LATERAL ETCH WITH BOTTOM PASSIVATION
2y 5m to grant Granted Mar 10, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

3-4
Expected OA Rounds
82%
Grant Probability
78%
With Interview (-3.6%)
2y 5m
Median Time to Grant
Moderate
PTA Risk
Based on 809 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month