Prosecution Insights
Last updated: April 19, 2026
Application No. 17/752,577

Isolation Features For Semiconductor Devices And Methods Of Fabricating The Same

Final Rejection §103
Filed
May 24, 2022
Examiner
SMITH, BRADLEY
Art Unit
2817
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Taiwan Semiconductor Manufacturing Company Ltd.
OA Round
2 (Final)
80%
Grant Probability
Favorable
3-4
OA Rounds
2y 6m
To Grant
76%
With Interview

Examiner Intelligence

Grants 80% — above average
80%
Career Allow Rate
695 granted / 873 resolved
+11.6% vs TC avg
Minimal -3% lift
Without
With
+-3.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
37 currently pending
Career history
910
Total Applications
across all art units

Statute-Specific Performance

§101
2.6%
-37.4% vs TC avg
§103
42.6%
+2.6% vs TC avg
§102
25.5%
-14.5% vs TC avg
§112
24.8%
-15.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 873 resolved cases

Office Action

§103
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 filed 12/16/23 have been fully considered but they are not persuasive. Regarding claim 1, the applicant amended the subject matter of claim 8 into claim 1. Claim 8 was previously rejected over Wu and Liao. The applicant has not challenged the combination of Wu and Liao. Therefore, the examiner has maintained the rejection using the combination of Wu and Liao. Applicant’s arguments with respect to claim(s) 21-24 have been considered but are moot because the new ground of rejection below. 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. Claim(s) 1 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. (US 2018/0151414) and Liao et al. (US 9,620,503). Regarding claim 1, Wu et al. et al. disclose a first portion including a first active region (F7)(fig 8) protruding from a substrate (110), and a second portion including a second active region (F3) protruding from the substrate; depositing a dielectric layer (200)(fig. 8) over the workpiece to fill a trench between the first active region and the second active region; and recessing the dielectric layer to form an isolation feature in the trench (fig. 13), the isolation feature comprising a first edge region (192,193) surrounding a bottom portion of the first active region(F7), a second edge region (172,173) surrounding a bottom portion of the second active region(F3), and a central region (between F3 and middle F7) having a substantially planar top surface and extending between the first edge region and the second edge region, wherein a height of the first edge region (thickness of insulation in 192,193) is smaller than a height of the second edge region(thickness of insulation in 172,173). Wu fails to explicitly disclose a thickness of the first edge region is greater than a thickness of the central region. Liao et al. disclose a thickness of the first edge region (211a) is greater than a thickness (T1) of the central region (fig. 3E). The prior art included each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the elements as claimed by known methods (creating an edge region with a greater thickness), and that in combination, each element merely performs the same function as it does separately. One of ordinary skill in the art would have recognized that the results of the combination were predictable (would create an edge region with a greater thickness). Claim(s) 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. (US 2018/0151414) and Paul et al. (US 2020/0111798). Regarding claim 21, Wu et al. et al. disclose forming a first active region (F3) including a first base region protruded from a substrate; forming a second active region (F4) including a second base region protruded from the substrate; forming an isolation feature (173) disposed between the first base region and the second base region, wherein the isolation feature comprises a first portion (253) interfacing a lower portion of a sidewall of the first base region and a second portion (281) interfacing a sidewall of the second base region, wherein a top surface of the first portion of the isolation feature is below a top surface of the second portion of the isolation feature (fig. 13). Wu et al. fails to disclose a first plurality of channel layers over the first base region; and a second plurality of channel layers over the second base region. Paul et al. disclose a first plurality of channel layers (601) (left stack in fig. 6C) and a second plurality of channel layers (601) (right stack in fig. 6C)[0067]. The combination of Wu et al. and Paul et al. a first plurality of channel layers (Paul et al.) over the first base region (Wu et al.) and a second plurality of channel layers (Paul et al.) over the second base region (Wu et al.). The prior art included each element claimed, although not necessarily in a single prior art reference, with the only difference between the claimed invention and the prior art being the lack of actual combination of the elements in a single prior art reference. One of ordinary skill in the art could have combined the elements as claimed by known methods (forming a multiple channel regions), and that in combination, each element merely performs the same function as it does separately. One of ordinary skill in the art would have recognized that the results of the combination were predictable (the multiple channels would allow for increased device density and reduced area [Paul 0002] and low leakage [applicant’s specification, 0002]). Allowable Subject Matter Claims 11-16 are allowed. Claims 2-7, 9-10 and 22-25 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: wherein the recessing of the dielectric layer to form the isolation feature in the trench comprises:forming a first pattern film over the second portion of the workpiece;performing a first etching process to recess a portion of the dielectric layer exposed by the first pattern film to form the first edge region and a portion of the central region of the isolation feature in the first portion of the workpiece;forming a second pattern film over the first portion of the workpiece; andperforming a second etching process to recess another portion of the dielectric layer exposed by the second pattern film to form the second edge region and a rest of the central region of the isolation feature in the second portion of the workpiece (claims 2-4) wherein a width of the second edge region is greater than a width of the first edge region (claim 5) :recessing source/drain regions of the first active region to form first source/drain openings;recessing source/drain regions of the second active region to form second source/drain openings; andforming p-type source/drain features in the first source/drain openings and n-type source/drain features in the second source/drain openings (claim 6-7) the first active region and the second active region each include a vertical stack of semiconductor layers and a portion of the substrate directly under the vertical stack of semiconductor layers, the vertical stack of semiconductor layers comprising a plurality of alternating channel layers and sacrificial layers (claims 9-10) a vertical stack of alternating first semiconductor layers and second semiconductor layers over a substrate; patterning the vertical stack and a portion of the substrate to form a first fin-shaped structure and a second fin-shaped structure, the first fin-shaped structure comprising a first portion of the vertical stack and a first mesa structure directly under the first portion of the vertical stack, the second fin-shaped structure comprising a second portion of the vertical stack and a second mesa structure directly under the second portion of the vertical stack; depositing a dielectric layer over workpiece to fill a trench between the first fin-shaped structure and the second fin-shaped structure; recessing a first portion of the dielectric layer to form a first isolation feature surrounding a bottom portion of the first fin-shaped structure; and recessing a second portion of the dielectric layer to form a second isolation feature surrounding a bottom portion of the second fin-shaped structure, wherein a height of the second isolation feature is greater than a height of the first isolation feature (claim 11-16) in a cross-sectional view cut through the first active region, the second active region, and the isolation feature, an entirety of the sidewall of the second base region is covered by the isolation feature (claim 22) forming a gate structure over the first active region and the second active region and extending on the isolation feature, wherein the gate structure further extends along an upper portion of the sidewall of the first base region (claim 23) forming a p-type source/drain feature over a source/drain region of the first active region; and forming an n-type source/drain feature over a source/drain region of the second active region (claim 24) the height of the first edge region is less than the height of the second edge region (claim 25). 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 BRADLEY K SMITH whose telephone number is (571)272-1884. The examiner can normally be reached Monday-Friday, 10am-6pm. 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, Marlon Fletcher can be reached at 571-272-2063. 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. /BRADLEY SMITH/Primary Examiner, Art Unit 2817
Read full office action

Prosecution Timeline

May 24, 2022
Application Filed
Sep 05, 2025
Non-Final Rejection — §103
Dec 16, 2025
Response Filed
Feb 17, 2026
Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
80%
Grant Probability
76%
With Interview (-3.1%)
2y 6m
Median Time to Grant
Moderate
PTA Risk
Based on 873 resolved cases by this examiner. Grant probability derived from career allow rate.

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