Prosecution Insights
Last updated: April 19, 2026
Application No. 18/137,797

HETEROEPITAXIAL SEMICONDUCTOR DEVICES WITH ENHANCED THERMAL DISSIPATION

Final Rejection §112
Filed
Apr 21, 2023
Examiner
KIM, JAY C
Art Unit
2815
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Wolfspeed, Inc.
OA Round
2 (Final)
48%
Grant Probability
Moderate
3-4
OA Rounds
3y 8m
To Grant
70%
With Interview

Examiner Intelligence

Grants 48% of resolved cases
48%
Career Allow Rate
412 granted / 849 resolved
-19.5% vs TC avg
Strong +22% interview lift
Without
With
+21.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 8m
Avg Prosecution
67 currently pending
Career history
916
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
39.1%
-0.9% vs TC avg
§102
19.5%
-20.5% vs TC avg
§112
39.6%
-0.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 849 resolved cases

Office Action

§112
DETAILED ACTION This Office Action is in response to Amendment filed December 22, 2025. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Election/Restrictions Claims 26-34 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim, because Applicants elected species A drawn to the embodiment shown in Figs. 2A and 3 of current application without traverse on August 29, 2025, which comprises trenches as recited in the amended claim 14, while the amended claim 26 and its dependent claims are directed to the nonelected species B shown in Figs. 2, 3B and 5A of current application, which comprises pits as recited in the amended claim 26. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 14, 17-19, 22-24 and 35 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claims contain subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventors, at the time the application was filed, had possession of the claimed invention. (1) Regarding claim 14, Applicants originally disclosed in paragraph [0013] of current application that “The surface portion 122C resides between the surface portions 122A and 122B and corresponds to a gate region of the HEMT 100” describing Fig. 1 of current application, which is directed to a “RELATED ART” rather than being directed to Applicants’ invention. Therefore, Applicants did not originally disclose “at least one gate region” “wherein the at least one gate region extends in a first direction” as recited on lines 6-7, because (a) Applicants disclosed “a gate region” only for a “RELATED ART” rather than for the claimed invention, (b) Applicants did not originally disclose how “a gate region” is defined, i.e. the gate region is a region where (i) a gate electrode is in direct contact with a topmost semiconductor layer, (ii) a gate electrode is in direct contact with a gate insulator layer, (iii) a gate electrode overlaps with the underlying device structure in plan view, etc., and (c) furthermore, as disclosed in paragraph [0013] of current application, Applicants may have insinuated that “a gate region” is a surface portion or a surface area, and in this case, Applicants did not originally disclose that “the at least one gate region extends in a first direction” as recited on line 7 since Applicants did not originally disclose how an extension direction of a surface area can be defined, either. (2) Also regarding claim 14, Applicants did not originally disclose that “the elongated trenches extend in a second direction, wherein the second direction is parallel to the first direction” as recited on lines 12-13, because (a) “the first direction” refers to a direction in which “at least one gate region extends” as recited on line 7, (b) as discussed above, Applicants did not originally disclose or define what a “gate region” refers to, and (c) therefore, “the first direction” is not well-defined, and thus Applicants did not originally disclose that “the elongated trenches extend in a second direction, wherein the second direction is parallel to the first direction” as recited on lines 12-13 since Applicants did not originally disclose “the first direction” in the first place. (3) Further regarding claim 14, Applicants did not originally disclose that “the elongated trenches extend in a second direction, wherein the second direction is parallel to the first direction” as recited on lines 12-13, because (a) if arguendo the claimed “at least gate region” refers to a region of the heteroepitaxial layer 215 shown in Fig. 2 of current application that is disposed directly under the metal gate contact 112, then the direction in which the elongated trenches extend, i.e. the claimed second direction, is a lateral direction in Fig. 3A of current application, which is a direction in which the trenches 210 extend, while the first direction in which the at least one gate region extend should be an up and down direction in Fig. 3A of current application since the metal gate contact 112 has a longer size along the up and down direction in comparison to the lateral direction in Fig. 3A of current application, (b) Applicants may have hinted at this issue by the new claim 35 that recites that “the second direction is perpendicular to the first direction”, which however is contradictory to the limitation recited on lines 12-13 of the amended claim 14, and (c) therefore, if arguendo the claimed “at least gate region” refers to a region of the heteroepitaxial layer 215 shown in Fig. 2 of current application that is disposed directly under the metal gate contact 112, Applicants originally disclosed that the second direction is orthogonal or perpendicular to the first direction rather than the second direction being parallel to the first direction as recited on lines 12-13 of the amended claim 14. Claims 17-19, 22-24 and 35 depend on claim 14, and therefore, claims 17-19, 22-24 and 35 also fail to comply with the written description requirement. The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 14, 17-19, 22-24 and 35 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. (1) Regarding claim 14, it is not clear what “A semiconductor device” recited in the preamble refers to, because (a) Applicants do not claim “A semiconductor device” per se, but rather claim that the semiconductor device comprises “at least one gate region” on lines 6-7, (b) therefore, if “A semiconductor device” is a single transistor device, for example, as implied in claim 23, the amended claim 14 may fail to comply with the written description requirement since Applicants did not originally disclose a single transistor device comprising one or more gate regions, which can be two or more gate regions, and (c) if “A semiconductor device” refers to a plurality of transistor devices, it is not clear whether the plurality of transistor devices are electrically connected to with each other to constitute “A semiconductor device”. (2) Also regarding claim 14, it is not clear whether the limitation “the semiconductor substrate comprises a semiconductor material having a thermal conductivity greater than about 50 W/m·K” recited on lines 2-3 suggests that the semiconductor substrate itself has “a thermal conductivity greater than about 50 W/m·K” or “a semiconductor material” has “a thermal conductivity greater than about 50 W/m·K”, because it appears that Applicants claim that “a semiconductor material” has “a thermal conductivity greater than about 50 W/m·K”, which would suggest that the claimed semiconductor substrate may not have “a thermal conductivity greater than about 50 W/m·K” since a thermal conductivity of a material may not exactly be the same with a thermal conductivity of a substrate formed from “a material” depending on the shape or configuration of “a substrate”. (3) Further regarding claim 14, it is not clear how “the at least one gate region extends in a first direction” as recited on line 7, because (a) as discussed above, Applicants did not originally disclose what a “gate region” refers to, (b) if arguendo “the at least one gate region” refer to surface portion(s) or surface area(s), it is not clear how surface portions or surface areas can extend in any direction since surface portions or surface areas do not have any particular direction in which the surface portions or surface areas extend, and (c) therefore, the claimed “at least one gate region” should be a three dimensional object, but it is not clear what “the at least one gate region” refer to, and it is not clear how “the at least one gate region” can be unambiguously defined. Claims 17-19, 22-24 and 35 depend on claim 14, and therefore, claims 17-19, 22-24 and 35 are also indefinite. (4) Regarding claim 35, it is not clear how “the second direction is parallel to the first direction” as recited on line 13 of the amended claim 14, and then “the second direction is perpendicular to the first direction” as recited in claim 35, because (a) these two limitations are contradictory to each other, and (b) therefore, it is not clear whether the claimed dependency of claim 35 is correct. Response to Arguments Applicants’ arguments with respect to claims 14 and 26 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Detzel et al. (US 11,257,941) Applicants' amendment necessitated the new ground of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicants are 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 JAY C KIM whose telephone number is (571) 270-1620. The examiner can normally be reached 8:00 AM - 6:00 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, Joshua Benitez can be reached at (571) 270-1435. 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. /J.K./Primary Examiner, Art Unit 2815 March 3, 2026 /JAY C KIM/Primary Examiner, Art Unit 2815
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Prosecution Timeline

Apr 21, 2023
Application Filed
Sep 24, 2025
Non-Final Rejection — §112
Dec 22, 2025
Response Filed
Mar 03, 2026
Final Rejection — §112 (current)

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Prosecution Projections

3-4
Expected OA Rounds
48%
Grant Probability
70%
With Interview (+21.9%)
3y 8m
Median Time to Grant
Moderate
PTA Risk
Based on 849 resolved cases by this examiner. Grant probability derived from career allow rate.

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